Nucharin Songsasen is a Research Biologist and the Center Head of the Center for Species Survival. She joined the Smithsonian in 2002 when offered the opportunity to study the reproductive biology of domestic and wild carnivores. Over the years, she built the Global Canid Conservation Program and expanded this conservation and research initiative from a laboratory setting to field conservation in range countries, including Brazil and Thailand.

Nucharin is a leading expert in the field of carnivore reproductive biology, especially canids (dog-like species). Research conducted in her laboratory focuses on developing innovative technologies to rescuing valuable genetics from wild canids and felids, while improving human reproductive health. In addition to reproductive research, she has collaborated with SCBI scientists and developed partnerships with national and international governmental and non-governmental organizations to address many threats to the sustainability of wild canids, including the maned wolf, dhole, red wolf, swift fox, and African painted dog, living in zoos or the wild. Since 2009, she has a collaborative research that focuses on better understand the reproductive biology and endocrinology of the whooping crane and identifying the causes of poor reproduction in this endangered species. She also expands avian research to include the Guam king fisher and white naped crane.

Nucharin received her Doctor of Veterinary Medicine degree from the Kasetsart University in Thailand, and Master of Science and doctoral degrees from the University of Guelph in Canada.

Article

• Stewart, Samantha, White, Alisa, Ou, Wenquan, Liu, Wei, Nagashima, Jennifer, Songsasen, Nucharin, and He, Xiaoming. 2024. "Controlled Ice Nucleation with a Sand-PDMS Film Device Enhances Cryopreservation of Mouse Preantral Ovarian Follicles." Journal of Medical Devices, 1–27. https://doi.org/10.1115/1.4066445. 2024
• Saylor, Erin M., Kouba, Andrew J., Boudreau, Melanie R., Songsasen, Nucharin, and Kouba, Carrie K. 2024. "Efficacy of salmon GnRHa, Ovaprim® and hCG for hormonal stimulation of spermiation in the Fowler’s toad (Anaxyrus fowleri)." Conservation Physiology, 12, (1). https://doi.org/10.1093/conphys/coae056. 2024
• Bragg, Morgan, Muletz-Wolz, Carly, Songsasen, Nucharin, and Freeman, Elizabeth W. 2024. "Kibble diet is associated with higher faecal glucocorticoid metabolite concentrations in zoo-managed red wolves ( Canis rufus )." Conservation Physiology, 12, (1). https://doi.org/10.1093/conphys/coae008. 2024
• Chen, Devin M., Chen, Li-Dunn, Kouba, Carrie K., Songsasen, Nucharin, Roth, Terri L., Allen, Peter J., and Kouba, Andrew J. 2024. "Oral administration of GnRH via a cricket vehicle stimulates spermiation in tiger salamanders (Ambystoma tigrinum)." PLOS ONE, 19, (7). https://doi.org/10.1371/journal.pone.0289995. 2024
• Nagashima, Jennifer B., Zenilman, Shoshana, Raab, April, Aranda-Espinoza, Helim, and Songsasen, Nucharin. 2023. "Comparative Tensile Properties and Collagen Patterns in Domestic Cat (Felis catus) and Dog (Canis lupus familiaris) Ovarian Cortical Tissues." Bioengineering, 10, (11). https://doi.org/10.3390/bioengineering10111285. 2023
• Hartzler, Kate E., McCartney, Chiara, Songsasen, Nucharin, and Nagashima, Jennifer B. 2023. "Cryopreservation of African painted dog (Lycaon pictus) ovarian tissue." Frontiers in Veterinary Science, 10. https://doi.org/10.3389/fvets.2023.1134726. 2023
• De los Reyes, Monica, Songsasen, Nucharin, and Herrick, Jason. 2023. "Editorial: Advances in reproductive biotechnologies in carnivores." Frontiers in Veterinary Science, 10. https://doi.org/10.3389/fvets.2023.1123368. 2023
• Brown, Megan E., Pukazhenthi, Budhan, Olsen, Glenn H., Crowe, Chris, Lynch, Warren, Songsasen, Nucharin, and Wildt, David E. 2023. "Low estradiol production of non-laying whooping cranes (Grus americana) is associated with the failure of small follicles to enter follicular hierarchy." General and comparative endocrinology, 338. https://doi.org/10.1016/j.ygcen.2023.114280. 2023
• Leimgruber, Peter, Songsasen, Nucharin, Stabach, Jared A., Horning, Megan, Reed, Dolores, Buk, Tara, Harwood, Arielle, Layman, Lawrence, Mathews, Christopher, Vance, Morgan, Marinari, Paul, Helmick, Kelly E., Delaski, Kristina M., Ware, Lisa H., Jones, Julia C., Silva, Jose L. P., Laske, Timothy G., and Moraes, Rosana Nogueira. 2023. "Providing baseline data for conservation–Heart rate monitoring in captive scimitar-horned oryx." Frontiers in Physiology, 14. https://doi.org/10.3389/fphys.2023.1079008. 2023
• Sosale, Medhini S., Songsasen, Nucharin, İbiş, Osman, Edwards, Cody W., Figueiró, Henrique V., and Koepfli, Klaus-Peter. 2023. "The complete mitochondrial genome and phylogenetic characterization of two putative subspecies of golden jackal (Canis aureus cruesemanni and Canis aureus moreotica)." Gene, 866. https://doi.org/10.1016/j.gene.2023.147303. 2023
• Dahal, R., Nagashima, Jennifer B., Songsasen, Nucharin, and Wood, T. 2022. "150 The influence of follicular fluid extracellular vesicles on in vitro maturation of oocytes in the domestic cat." Reproduction, Fertility and Development, 34, (2) 313. https://doi.org/10.1071/RDv34n2Ab150. 2022
• Nagashima, Jennifer B. and Songsasen, Nucharin. 2022. "60 Follicular fluid extracellular vesicles: endocytosis and influence on domestic cat cumulus cells and oocytes." Reproduction, Fertility and Development, 34, (2) 266. https://doi.org/10.1071/RDv34n2Ab60. 2022
• Chavez, Daniel E., Gronau, Ilan, Hains, Taylor, Dikow, Rebecca B., Frandsen, Paul B., Figueiró, Henrique V., Garcez, Fabrício S., Tchaicka, Ligia, De Paula, Rogério C., Rodrigues, Flávio H. G., Jorge, Rodrigo S. P., Lima, Edson S., Songsasen, Nucharin, Johnson, Warren E., Eizirik, Eduardo, Koepfli, Klaus-Peter, and Wayne, Robert K. 2022. "Comparative genomics uncovers the evolutionary history, demography, and molecular adaptations of South American canids." Proceedings of the National Academy of Sciences of the United States of America, 119, (34). https://doi.org/10.1073/pnas.2205986119. 2022
• Nagashima, Jennifer B. and Songsasen, Nucharin. 2021. "Canid Reproductive Biology: Norm and Unique Aspects in Strategies and Mechanisms." Animals, 11, (3). https://doi.org/10.3390/ani11030653. 2021
• Jones, Marieke K., Huff, Thomas B., Freeman, Elizabeth W., and Songsasen, Nucharin. 2021. "Differential expression of urinary volatile organic compounds by sex, male reproductive status, and pairing status in the maned wolf (Chrysocyon brachyurus)." Plos One, 16, (8). https://doi.org/10.1371/journal.pone.0256388. 2021
• Nagashima, Jennifer B., Hill, Andrea M., and Songsasen, Nucharin. 2021. "In vitro development of mechanically and enzymatically isolated cat ovarian follicles." Reproduction and Fertility, 2, (1) 35–46. https://doi.org/10.1530/RAF-20-0067. 2021
• Moraes, Rosana N., Laske, Timothy G., Leimgruber, Peter, Stabach, Jared A., Marinari, Paul E., Horning, Megan M., Laske, Noelle R., Rodriguez, Juan V., Eye, Ginger N., Kordell, Jessica E., Gonzalez, Marissa, Eyring, Tom, Lemons, Christopher, Helmick, Kelly E., Delaski, Kristina M., Ware, Lisa H., Jones, Julia C., and Songsasen, Nucharin. 2021. "Inside out: heart rate monitoring to advance the welfare and conservation of maned wolves (Chrysocyon brachyurus)." Conservation Physiology, 9, (1). https://doi.org/10.1093/conphys/coab044. 2021
• De los Reyes, Monica and Songsasen, Nucharin. 2021. "New Insights in Canine Reproduction." Animals, 11, (7). https://doi.org/10.3390/ani11072021. 2021
• de Almeida Monteiro Melo Ferraz, Marcia, Nagashima, Jennifer Beth, Venzac, Bastien, Le Gac, Séverine, and Songsasen, Nucharin. 2020. "3D printed mold leachates in PDMS microfluidic devices." Scientific Reports, 10, (1) Article 994. https://doi.org/10.1038/s41598-020-57816-y. 2020
• de Almeida Monteiro Melo Ferraz, Marcia, Nagashima, Jennifer Beth, Venzac, Bastien, Le Gac, Séverine, and Songsasen, Nucharin. 2020. "A dog oviduct-on-a-chip model of serous tubal intraepithelial carcinoma." Scientific Reports, 10, (1) 1–11. https://doi.org/10.1038/s41598-020-58507-4. 2020
• Khoewsree, Noraset, Charaspet, Khwanrutai, Sukmasuang, Ronglarp-, Songsasen, Nucharin, Pla-Ard, Mananya, Thongbantum, Jidapa, Kongchaloem, Waraporn, and Srinopawan, Khanchit. 2020. "Abundance, prey, and activity period of dholes (Cuon alpinus) in Khao Yai National Park, Thailand." Biodiversitas Journal of Biological Diversity, 21, (1). https://doi.org/10.13057/biodiv/d210142. 2020
• Pukazhenthi, Budhan, Songsasen, Nucharin, Brown, Janine, Comizzoli, Pierre, Crosier, Adrienne, Hagedorn, Mary, Gratwicke, Brian, Pitt, William, and Monfort, Steven. 2020. "David E. Wildt-An Inspiring Leader in the Conservation of Wild Species." Journal of Heredity, 111, (4) 414–416. https://doi.org/10.1093/jhered/esaa013. 2020
• Noonan, Michael J., Fleming, Christen H., Tucker, Marlee A., Kays, Roland, Harrison, Autumn-Lynn, Crofoot, Margaret C., Abrahms, Briana, Alberts, Susan C., Ali, Abdullahi H., Altmann, Jeanne, Antunes, Pamela Castro, Attias, Nina, Belant, Jerrold L., Beyer, Dean E., Jr., Bidner, Laura R., Blaum, Niels, Boone, Randall B., Caillaud, Damien, de Paula, Rogerio Cunha, De la Torre, J. Antonio, Dekker, Jasja, DePerno, Christopher S., Farhadinia, Mohammad, Fennessy, Julian, Fichtel, Claudia et al. 2020. "Effects of body size on estimation of mammalian area requirements." Conservation Biology, 34, (4) 1017–1028. https://doi.org/10.1111/cobi.13495. 2020
• das Candeias, Isis Zanini, da motta Lima, Caio Filipe, Lemos, Frederico Gemesio, Spercoski, Katherinne Maria, de Oliveira, Claudio Alvarenga, Songsasen, Nucharin, and Vaz Guimaraes, Marcelo Alcindo de Barros. 2020. "First assessment of hoary fox (Lycalopex vetulus) seasonal ovarian cyclicity by non-invasive hormonal monitoring technique." Conservation Physiology, 8, (1) coaa039. https://doi.org/10.1093/conphys/coaa039. 2020
• de Almeida Monteiro Melo Ferraz, Marcia, Fujihara, Mayako, Nagashima, Jennifer Beth, Noonan, Michael James, Inoue-Murayama, Miho, and Songsasen, Nucharin. 2020. "Follicular extracellular vesicles enhance meiotic resumption of domestic cat vitrified oocytes." Scientific Reports, 10, (1). https://doi.org/10.1038/s41598-020-65497-w. 2020
• Bragg, Morgan, Freeman, Elizabeth W., Lim, Haw Chuan, Songsasen, Nucharin, and Muletz-Wolz, Carly R. 2020. "Gut Microbiomes Differ Among Dietary Types and Stool Consistency in the Captive Red Wolf (Canis rufus)." Frontiers in Microbiology, 11 Article 590212. https://doi.org/10.3389/fmicb.2020.590212. 2020
• Nagashima, Jennifer B., Ferraz,Marcia de Almeida Monteiro Melo, Kamen, Sarah H., and Songsasen, Nucharin. 2020. "Investigating media that support red wolf (Canis rufus) sperm viability and capacitation in vitro." Reproduction and Fertility, 1, (1) 83–92. https://doi.org/10.1530/RAF-20-0042. 2020
• Ferraz,Marcia de Almeida Monteiro Melo, Nagashima, Jennifer Beth, Noonan, Michael James, Crosier, Adrienne E., and Songsasen, Nucharin. 2020. "Oviductal Extracellular Vesicles Improve Post-Thaw Sperm Function in Red Wolves and Cheetahs." International Journal of Molecular Sciences, 21, (10). https://doi.org/10.3390/ijms21103733. 2020
• Thuwanut, Paweena, Comizzoli, Pierre, Pruksananonda, Kamthorn, Chatdarong, Kaywalee, and Songsasen, Nucharin. 2019. "Activation of adenosine monophosphate-activated protein kinase (AMPK) enhances energy metabolism, motility, and fertilizing ability of cryopreserved spermatozoa in domestic cat model." Journal of assisted reproduction and genetics, 36, (7) 1401–1412. https://doi.org/10.1007/s10815-019-01470-5. 2019
• Nagashima, Jennifer B., Wildt, David E., Travis, Alexander J., and Songsasen, Nucharin. 2019. "Activin promotes growth and antral cavity expansion in the dog ovarian follicle." Theriogenology, 129 168–177. https://doi.org/10.1016/j.theriogenology.2019.02.018. 2019
• Thongkittidilok, Chommanart, Doriguzzi, Nicole, Nagashima, Jennifer, Brown, Megan, Chansaenroj, Ajjima, and Songsasen, Nucharin. 2019. "Cilostamide and forskolin maintain gap junction function of incubated dog follicles." Theriogenology, 142 222–228. https://doi.org/10.1016/j.theriogenology.2019.09.034. 2019
• Chansaenroj, A., Songsasen, Nucharin, and Chatdarong, K. 2019. "Equine chorionic gonadotropin induces in vitro follicular growth from the multi-layered secondary developmental stage in cats." Theriogenology, 123 116–122. https://doi.org/10.1016/j.theriogenology.2018.09.040. 2019
• Brown, Megan E., Keefer, Carol L., and Songsasen, Nucharin. 2019. "Factors affecting captive whooping crane egg fertility: A retrospective analysis." Journal of Wildlife Management, 83, (6) 1377–1386. https://doi.org/10.1002/jwmg.21717. 2019
• Ferraz, M., Carothers, A., Dahal, R., Noonan, M. J., and Songsasen, N. 2019. "Oviductal extracellular vesicles interact with the spermatozoon's head and mid-piece and improves its motility and fertilizing ability in the domestic cat." Scientific Reports, 9, (1) Article 9484. https://doi.org/10.1038/s41598-019-45857-x. 2019
• Chansaenroj, Ajjima, Songsasen, Nucharin, Thongphakdee, Ampika, and Chatdarong, Kaywalee. 2019. "Restoration of tiger (Panthera tigris) follicles from frozen-thawed ovarian tissues." Thai Journal of Veterinary Medicine, 49, (2) 131–136. 2019
• Brown, Megan E., Singh, Ram P., Pukazhenthi, Budhan, Keefer, Carol L., and Songsasen, Nucharin. 2018. "Cryopreservation effects on sperm function and fertility in two threatened crane species." Cryobiology, 82 148–154. https://doi.org/10.1016/j.cryobiol.2018.01.010. 2018
• Nagashima, Jennifer B., El Assal, R., Songsasen, Nucharin, and Demirci, U. 2018. "Evaluation of an ovary-on-a-chip in large mammalian models: Species specificity and influence of follicle isolation status." Journal of Tissue Engineering and Regenerative Medicine, 12, (4) e1926–e1935. https://doi.org/10.1002/term.2623. 2018
• Thongkittidilok, Chommanart, Singh, Ram Pratap, Comizzoli, Pierre, Wildt, David E., and Songsasen, Nucharin. 2018. "Insulin promotes preantral follicle growth and antrum formation through temporal expression of genes regulating steroidogenesis and water transport in the cat." Reproduction Fertility and Development, 30, (10) 1369–1379. https://doi.org/10.1071/RD17454. 2018
• Jones, Marieke K., Reiter, Lauren E., Gilmore, Michael P., Freeman, Elizabeth W., and Songsasen, Nucharin. 2018. "Physiological impacts of housing maned wolves (Chrysocyon brachyurus) with female relatives or unrelated males." General and comparative endocrinology, 267 109–115. https://doi.org/10.1016/j.ygcen.2018.06.007. 2018
• Fujihara, Mayako, Yamamizu, Kohei, Comizzoli, Pierre, Wildt, David E., and Songsasen, Nucharin. 2018. "Retinoic acid promotes in vitro follicle activation in the cat ovary by regulating expression of matrix metalloproteinase 9." Plos One, 13, (8) 1–14. https://doi.org/10.1371/journal.pone.0202759. 2018
• Henson, Lauren H., Songsasen, Nucharin, Waddell, Will, Wolf, Karen N., Emmons, Louise H., Gonzalez, Susana, Freeman, Elizabeth, and Maldonado, Jesús E. 2017. "Characterization of Genetic Variation and Basis of Inflammatory Bowel Disease in the Toll-like Receptor 5 Gene of the Red Wolf and Maned Wolf." Endangered Species Research, 32 135–144. https://doi.org/10.3354/esr00790. 2017
• Songsasen, Nucharin, Henson, Lh, Tipkantha, W., Thongkittidilok, C., Henson, Jh, Chatdarong, K., and Comizzoli, Pierre. 2017. "Dynamic changes in mitochondrial DNA, distribution and activity within cat oocytes during folliculogenesis." Reproduction in Domestic Animals, 52, (Supplement S2) 71–76. https://doi.org/10.1111/rda.12851. 2017
• Songsasen, Nucharin, Nagashima, Jennifer B., and Thongkittidilok, C. 2017. "Endocrine and paracrine controls of canine follicular development and function." Reproduction in Domestic Animals, 52, (Supplement S2) 29–34. https://doi.org/10.1111/rda.12858. 2017
• Khonmee, Jaruwan, Rojanasthien, Suvichai, Thitaram, Chatchote, Sumretprasong, Jureerat, Aunsusin, Anurut, Chaisongkram, Chawin, and Songsasen, Nucharin. 2017. "Non-invasive endocrine monitoring indicates seasonal variations in gonadal hormone metabolites in dholes (Cuon alpinus)." Conservation Physiology, 5, (1). https://doi.org/10.1093/conphys/cox001. 2017
• Thongkittidilok, Chommanart, Wildt, David E., and Songsasen, Nucharin. 2017. "Responsiveness of intraovarian dog follicles in vitro to epidermal growth factor and vascular endothelial growth factor depends on ovarian donor age." Reproduction in Domestic Animals, 52, (Supplement S2) 114–122. https://doi.org/10.1111/rda.12852. 2017
• Songsasen, Nucharin, Thongkittidilok, Chommanart, Yamamizu, K., Wildt, David E., and Comizzoli, Pierre. 2017. "Short-term hypertonic exposure enhances in vitro follicle growth and meiotic competence of enclosed oocytes while modestly affecting mRNA expression of aquaporin and steroidogenic genes in the domestic cat model." Theriogenology, 90 228–236. https://doi.org/10.1016/j.theriogenology.2016.12.006. 2017
• Thuwanut, Paweena, Comizzoli, Pierre, Wildt, David E., Keefer, Carol L., and Songsasen, Nucharin. 2017. "Stem cell factor promotes in vitro ovarian follicle development in the domestic cat by upregulating c-kit mRNA expression and stimulating the phosphatidylinositol 3-kinase/AKT pathway." Reproduction Fertility and Development, 29, (7) 1356–1368. https://doi.org/10.1071/RD16071. 2017
• Nagashima, Jennifer B., Hansen, B. S., Songsasen, Nucharin, Travis, A. J., and Place, N. J. 2016. "Anti-Müllerian Hormone in the Domestic Dog during the Anestrus to Oestrous Transition." Reproduction in Domestic Animals, 51, (1) 158–164. https://doi.org/10.1111/rda.12660. 2016
• Herrick, Jason R., Mastromonaco, Gabriela, Songsasen, Nucharin, and Comizzoli, Pierre. 2016. "Biomaterials repositories: the science and business of biobanking." Reproduction, Fertility and Development, 28, (8). https://doi.org/10.1071/RDv28n8_FO. 2016
• Fujihara, M., Yamamizu, K., Wildt, David E., and Songsasen, Nucharin. 2016. "Expression pattern of matrix metalloproteinases changes during folliculogenesis in the cat ovary." Reproduction in Domestic Animals, 51, (5) 717–725. https://doi.org/10.1111/rda.12736. 2016
• Brown, Megan E., Converse, Sarah J., Chandler, Jane N., Shafer, Charles, Brown, Janine L., Keefer, Carol L., and Songsasen, Nucharin. 2016. "Female gonadal hormones and reproductive behaviors as key determinants of successful reproductive output of breeding Whooping Cranes (Grus americana)." General and comparative endocrinology, 230/231 158–165. https://doi.org/10.1016/j.ygcen.2016.04.009. 2016
• Panyaboriban, Saritvich, Pukazhenthi, Budhan S., Brown, Megan E., Crowe, Chris, Lynch, Warren E., Singh, Ram P., Techakumphu, Mongkol, and Songsasen, Nucharin. 2016. "Influence of cooling and thawing conditions and cryoprotectant concentration on frozen-thawed survival of white-naped crane (Antigone vipio) spermatozoa." Cryobiology, 73, (2) 209–215. https://doi.org/10.1016/j.cryobiol.2016.07.009. 2016
• Duncan, Francesca E., Zelinski, Mary, Gunn, Alexander H., Pahnke, Jennifer E., O'Neill, Conor L., Songsasen, Nucharin, Woodruff, Ryan I., and Woodruff, Teresa K. 2016. "Ovarian tissue transport to expand access to fertility preservation: from animals to clinical practice." Reproduction, 152, (6) R201–R210. https://doi.org/10.1530/REP-15-0598. 2016
• Wojtusik, Jessye, Pennington, Parker, Songsasen, Nucharin, Padilla, Luis R., Citino, Scott B., and Pukazhenthi, Budhan S. 2016. "Pretreatment of Addra gazelle (Nanger dama ruficollis) spermatozoa with cholesterol-loaded cyclodextrins improves cryosurvival." Cryobiology, 73, (3) 388–395. https://doi.org/10.1016/j.cryobiol.2016.08.012. 2016
• Panyaboriban, Saritvich, Singh, Ram Pratap, Songsasen, Nucharin, Padilla, Luis, Brown, Janine, Reed, Dolores, Techakumphu, Mongkol, and Pukazhenthi, Budhan S. 2016. "Reproductive seasonality and sperm cryopreservation in the male tufted deer (Elaphodus cephalophus)." Theriogenology, 86, (4) 914–923. https://doi.org/10.1016/j.theriogenology.2016.03.014. 2016
• Jenks, Kate E., Aikens, Ellen O., Songsasen, Nucharin, Calabrese, Justin, Fleming, Chris, Bhumpakphan, Naris, Wanghongsa, Sawai, Kanchanasaka, Budsabong, Songer, Melissa A., and Leimgruber, Peter. 2015. "Comparative movement analysis for a sympatric dhole and golden jackal in a human-dominated landscape." Raffles Bulletin of Zoology, 63 546–554. 2015
• Thongkittidilok, Chommanart, Tharasanit, Theerawat, Songsasen, Nucharin, Sananmuang, Thanida, Buarpung, Sirirak, and Techakumphu, Mongkol. 2015. "Epidermal growth factor improves developmental competence and embryonic quality of singly cultured domestic cat embryos." Journal of Reproduction and Development, 61, (4) 269–276. https://doi.org/10.1262/jrd.2014-167. 2015
• Nagashima, Jennifer B., Wildt, David E., Travis, Alexander J., and Songsasen, Nucharin. 2015. "Follicular size and stage and gonadotropin concentration affect alginate-encapsulated in vitro growth and survival of pre- and early antral dog follicles." Reproduction, Fertility and Development, 29, (2) 262–273. https://doi.org/10.1071/RD15004. 2015
• Nagashima, Jennifer B., Sylvester, Skylar R., Nelson, Jacquelyn L., Cheong, Soon Hon, Mukai, Chinatsu, Lambo, Colleen, Flanders, James A., Meyers-Wallen, Vicki, Songsasen, Nucharin, and Travis, Alexander J. 2015. "Live Births from Domestic Dog (Canis familiaris) Embryos Produced by In Vitro Fertilization." PloS One, 10, (12). https://doi.org/10.1371/journal.pone.0143930. 2015
• Brown, M. E., Converse, S. J., Chandler, J. N., Crosier, A. L., Lynch, Warren E., Wildt, David E., Keefer, C. L., and Songsasen, Nucharin. 2015. "Time within reproductive season, but not age or inbreeding coefficient, affects seminal and sperm quality in the whooping crane (Grus americana)." Reproduction Fertility and Development, 29, (2) 294–306. https://doi.org/10.1071/RD15251. 2015
• Fujihara, Mayako, Comizzoli, Pierre, Keefer, Carol L., Wildt, David E., and Songsasen, Nucharin. 2014. "Epidermal Growth Factor (EGF) Sustains In Vitro Primordial Follicle Viability by Enhancing Stromal Cell Proliferation via MAPK and PI3K Pathways in the Prepubertal, but Not Adult Cat Ovary." Biology of Reproduction, 90, (4). https://doi.org/10.1095/biolreprod.113.115089. 2014
• Pukazhenthi, Budhan S., Johnson, Aime, Guthrie, H. David, Songsasen, Nucharin, Padilla, Luis R., Wolfe, Barbara A., da Silva, Marco Coutinho, Alvarenga, Marco A., and Wildt, David E. 2014. "Improved Sperm Cryosurvival in Diluents Containing Amides versus Glycerol in the Przewalski's Horse (Equus ferus przewalskii)." Cryobiology, 68, (2) 205–214. https://doi.org/10.1016/j.cryobiol.2014.01.013. 2014
• Johnson, Amy E. M., Freeman, Elizabeth W., Colgin, Mark, McDonough, Caitlin, and Songsasen, Nucharin. 2014. "Induction of ovarian activity and ovulation in an induced ovulator, the maned wolf (Chrysocyon brachyurus), using GnRH agonist and recombinant LH." Theriogenology, 82, (1) 71–79. https://doi.org/10.1016/j.theriogenology.2014.03.009. 2014
• Jenks, Kate E., Songsasen, Nucharin, Kanchanasaka, Budsabong, Leimgruber, Peter, and Fuller, Todd K. 2014. "Local people's attitudes and perceptions of dholes (Cuon alpinus) around protected areas in southeastern Thailand." Tropical conservation science, 7, (4) 765–780. https://doi.org/10.1177/194008291400700413. 2014
• Collins, C. Wynne, Monfort, Steven L., Vick, Mandi M., Wolfe, Barbara A., Weiss, Rachael B., Keefer, Carol L., and Songsasen, Nucharin. 2014. "Oral and injectable synthetic progestagens effectively manipulate the estrous cycle in the Przewalski's horse (Equus ferus przewalskii)." Animal Reproduction Science, 148, (1/2) 42–52. https://doi.org/10.1016/j.anireprosci.2014.03.018. 2014
• Johnson, Amy E. M., Freeman, Elizabeth W., Wildt, David E., and Songsasen, Nucharin. 2014. "Spermatozoa from the maned wolf (Chrysocyon brachyurus) display typical canid hyper-sensitivity to osmotic and freezing-induced injury, but respond favorably to dimethyl sulfoxide." Cryobiology, 68, (3) 361–370. https://doi.org/10.1016/j.cryobiol.2014.04.004. 2014
• Jenks, Kate E., Songsasen, Nucharin, Kanchanasaka, Budsabong, Bhumpakphan, Naris, Wanghongsa, Sawai, and Leimgruber, Peter. 2013. "Community attitudes toward protected areas in Thailand." Natural History Bulletin of the Siam Society, 59, (2) 65–76. 2013
• Lynam, Antony J., Jenks, Kate E., Tantipisanuh, Naruemon, Chutipong, Wanlop, Ngoprasert, Dusit, Gale, George A., Steinmetz, Robert, Sukmasuang, Ronglarp, Bhumpakphan, Naris, Grassman, Lon I., Jr., Cutter, Passanan, Kitamura, Shumpei, Reed, David H., Baker, Megan C., McShea, William J., Songsasen, Nucharin, and Leimgruber, Peter. 2013. "Terrestrial Activity Patterns of Wild Cats from Camera-Trapping." Raffles Bulletin of Zoology, 61, (1) 407–415. 2013
• Spercoski, Katherinne M., Morais , Rosana N., Morato, Ronaldo G., De Paula, Rogério C., Azevedo, Fernanda C., May-Júnior, Joares A., Santos, Jean P., Reghelin, Angela L., Wildt, David E., and Songsasen, Nucharin. 2012. "Adrenal activity in maned wolves is higher on farmlands and park boundaries than within protected areas." General and comparative endocrinology, 179, (2) 232–240. https://doi.org/10.1016/j.ygcen.2012.08.002. 2012
• Jenks, Kate E., Songsasen, Nucharin, and Leimgruber, Peter. 2012. "Camera trap records of dholes in Khao Ang Rue Nai Wildlife Sanctuary, Thailand." Canid News, 15, (4) 1–5. 2012
• Fujihara, Mayako, Comizzoli, Pierre, Wildt, David E., and Songsasen, Nucharin. 2012. "Cat and Dog Primordial Follicles Enclosed in Ovarian Cortex Sustain Viability after In vitro Culture on Agarose Gel in a Protein-Free Medium." Reproduction in Domestic Animals, 47, (Supplement S6) 102–108. https://doi.org/10.1111/rda.12022. 2012
• Comizzoli, Pierre, Songsasen, Nucharin, Hagedorn, Mary M., and Wildt, David E. 2012. "Comparative cryobiological traits and requirements for gametes and gonadal tissues collected from wildlife species." Theriogenology, 78, (8) 1666–1681. https://doi.org/10.1016/j.theriogenology.2012.04.008. 2012
• Jenks, Kate E., Kitamura, Shumpei, Lynam, Antony J., Ngoprasert, Dusit, Chutipong, Wanlop, Steinmetz, Robert, Sukmasuang, Ronglarp, Grassman, Lon I., Jr., Cutter, Passanan, Tantipisanuh, Naruemon, Bhumpakphan, Naris, Gale, George A., Reed, David H., Leimgruber, Peter, and Songsasen, Nucharin. 2012. "Mapping the distribution of dholes, Cuon alpinus (Canidae, Carnivora), in Thailand." Mammalia, 76, (2) 175–184. https://doi.org/10.1515/mammalia-2011-0063. 2012
• Ngoprasert, Dusit, Lynam, Antony J., Sukmasuang, Ronglarp, Tantipisanuh, Naruemon, Chutipong, Wanlop, Steinmetz, Robert, Jenks, Kate E., Gale, George A., Grassman, Lon I., Kitamura, Shumpei, Howard, JoGayle, Cutter, Passanan, Cutter, Peter, Leimgruber, Peter, Songsasen, Nucharin, and Reed, David H. 2012. "Occurrence of Three Felids across a Network of Protected Areas in Thailand: Prey, Intraguild, and Habitat Associations." Biotropica, 44, (6) 810–817. https://doi.org/10.1111/j.1744-7429.2012.00878.x. 2012
• Songsasen, Nucharin, Comizzoli, Pierre, Nagashima, Jennifer B., Fujihara, Mayako, and Wildt, David E. 2012. "The Domestic Dog and Cat as Models for Understanding the Regulation of Ovarian Follicle Development In Vitro." Reproduction in Domestic Animals, 47, (Supplement S6) 13–18. https://doi.org/10.1111/rda.12067. 2012
• Songsasen, Nucharin, Wesselowski, Sonya, Carpenter, James W., and Wildt, David E. 2012. "The ability to achieve meiotic maturation in the dog oocyte is linked to glycolysis and glutamine oxidation." Molecular reproduction and development, 79, (3) 186–196. https://doi.org/10.1002/mrd.22011. 2012
• Songsasen, Nucharin, Guzy, C., and Wildt, David E. 2011. "121 Alginate-Fibrin Gel Matrix Promotes in Vitro Growth of Dog Secondary Follicles." Reproduction, Fertility and Development, 24, (1) 173. https://doi.org/10.1071/RDv24n1Ab121. 2011
• Collins, Christina Wynne, Songsasen, Nucharin, Vick, Mandi M., Wolfe, Barbara A., Weiss, Rachael B., Keefer, Carol L., and Monfort, Steven L. 2011. "Abnormal Reproductive Patterns in Przewalski's Mares Are Associated with a Loss in Gene Diversity." Biology of reproduction, 86, (2). https://doi.org/10.1095/biolreprod.111.092676. 2011
• Rudert, S., Brown, Janine L., Gansloßer, U., Möbius, G., and Songsasen, Nucharin. 2011. "Activity pattern, reproductive behaviors and gonadal hormones in the raccoon dog (Nyctereutes procyonoides)." Zoo Biology, 30, (2) 134–148. https://doi.org/10.1002/zoo.20315. 2011
• Pukazhenthi, Budhan S., Hagedorn, Mary M., Comizzoli, Pierre, Songsasen, Nucharin, and Wildt, David E. 2011. "Cryopreserving endangered species gametes, embryos and gonadal tissue: Challenges, successes and future directions." Cryobiology, 63, (3) 308–309. https://doi.org/10.1016/j.cryobiol.2011.09.014. 2011
• Songsasen, Nucharin, Woodruff, Teresa K., and Wildt, David E. 2011. "In vitro growth and steroidogenesis of dog follicles as influenced by the physical and hormonal microenvironment." Reproduction, 142 113–122. https://doi.org/10.1530/REP-10-0442. 2011
• Jenks, K. E., Wanghongsa, S., Songsasen, Nucharin, Leimgruber, Peter, and Howard, JoGayle. 2010. "Camera-trap evidence of large-spotted civet Viverra megaspila in Khao Ang Rue Nai Wildlife Sanctuary and Khao Yai National Park, Thailand." Small Carnivore Conservation, 42 19–21. 2010
• Siriaroonrat, B., Comizzoli, Pierre, Songsasen, Nucharin, Monfort, Steven L., Wildt, David E., and Pukazhenthi, Budhan S. 2010. "Oocyte quality and estradiol supplementation affect in vitro maturation success in the white-tailed deer (Odocoileus virginianus)." Theriogenology, 73, (1) 112–119. https://doi.org/10.1016/j.theriogenology.2009.08.007. 2010
• Songsasen, Nucharin and Rodden, Melissa D. 2010. "The role of the Species Survival Plan in Maned wolf Chrysocyon brachyurus conservation." International Zoo Yearbook, 44 136–148. 2010
• Comizzoli, Pierre, Crosier, Adrienne E., Songsasen, Nucharin, Szykman, Micaela, Howard, JoGayle, and Wildt, David E. 2009. "Advances in reproductive science for wild carnivore conservation." Reproduction in Domestic Animals, 44 47–52. 2009
• Yu, I., Leibo, S. P., Songsasen, Nucharin, Dresser, B. L., and Kim, I. 2009. "Cryopreservation of Canine Ovarian and Testicular Fibroblasts." Cryoletters, 30, (3) 190–201. 2009
• Songsasen, Nucharin, Fickes, A., Pukazhenthi, Budhan S., and Wildt, David E. 2009. "Follicular morphology, oocyte diameter and localization of fibroblast growth factors in the domestic dog ovary." Reproduction in Domestic Animals (Supplement 2), 44 65–70. 2009
• May-Júnior, J. A., Songsasen, Nucharin, Azevedo, F. C., Santos, J. P., Paula, R. C., Rodrigues, F. H. G., Rodden, Melissa D., Wildt, David E., and Morato, R. G. 2009. "Hematology and blood chemistry status differs in free-ranging maned wolves (Chrysocyon brachyurus) living in the Serra da Canastra National Park (Brazil) versus adjacent farmlands." Journal of Zoo and Wildlife Diseases, 45 81–90. 2009
• Wildt, David E., Comizzoli, Pierre, Pukazhenthi, Budhan S., and Songsasen, Nucharin. 2009. "Lessons from biodiversity - the value of nontraditional species to advance reproductive science, conservation, and human health." Molecular reproduction and development, 77, (5) 397–409. https://doi.org/10.1002/mrd.21137. 2009
• Thongtip, N., Saikhun, J., Mahasawangkul, M., Kornkaewrat, K., Pongsopavijutr, P., Songsasen, Nucharin, and Pinyopummin, A. 2008. "Potential factors affecting semen quality in the Asian elephant (Elephas maximus)." Reproductive Biology and Endocrinology, 17 6–9. 2008
• Cummings, D., Brown, Janine L., Rodden, Melissa D., and Songsasen, Nucharin. 2007. "Behavioral and physiologic responses to environmental enrichment in the maned wolf (Chrysocyon brachyurus)." Zoo Biology, 26, (5) 331–343. https://doi.org/10.1002/zoo.20138. 2007
• Songsasen, Nucharin, Spindler, Rebecca E., and Wildt, David E. 2007. "Requirement for, and patterns of, pyruvate and glutamine metabolism in the domestic dog oocyte in vitro." Molecular reproduction and development, 74 870–877. 2007

Chapter

• Nagashima, J. B., Travis, A. J., and Songsasen, Nucharin. 2019. "The Domestic Dog Embryo: In Vitro Fertilization, Culture, and Transfer." In Comparative Embryo Culture: Methods and Protocols. Herrick, Jason R., editor. 247–267. New York: Springer. In Methods in Molecular Biology. 2019
• Kester, Marieke E., Freeman, Elizabeth W., Songsasen, Nucharin, and Huff, Thomas B. 2016. "Automated Headspace Solid-Phase Microextraction of Urinary VOCs from Eleven Maned Wolves (Chrysocyon brachyurus): A Recursive Workflow for GC–MS Analysis." In Chemical Signals in Vertebrates 13. Schulte, Bruce A., Goodwin, Thomas E., and Ferkin, Michael H., editors. 477–498. Springer International Publishing. https://doi.org/10.1007/978-3-319-22026-0_31. 2016
• Jewgenow, Katarina and Songsasen, Nucharin. 2014. "Reproduction and Advances in Reproductive Studies in Carnivores." In Reproductive Sciences in Animal Conservation. Holt, W. V., Brown, Janine L., and Comizzoli, Pierre, editors. 205–239. Berlin, Germany: Springer-Verlag Berlin. In Advances in Experimental Medicine and Biology, 753. https://doi.org/10.1007/978-1-4939-0820-2_10. 2014
• Goodwin, Thomas E., Songsasen, Nucharin, Broederdorf, Laura J., Burkert, Blake A., Chen, C. J., Jackson, Stephen R., Keplinger, K. B., Rountree, Margaret E., Waldrip, Zach J., Weddell, Margaret E., Desrochers, Linda P., Baker,William K., Jr., and Helsper, Johannes P. F. G. 2013. "Hemiterpenoids and Pyrazines in the odoriferous urine of the maned wolf (Chrysocyon brachyurus)." In Chemical Signals in Vertebrates 12. East, Marion L. and Dehnhard, Martin, editors. 171–184. Springer New York. 2013
• Songsasen, Nucharin. 2013. "Reproduction and Factors Affecting Reproductive Success in the Maned Wolf." In Ecology and Conservation of the Maned Wolf: Multidisciplinary Perspectives. Consorte-McCrea, Adriana G. and Ferraz, E., editors. Boca Raton, FL: Taylor and Francis Group, CRC Press. 2013
• Comizzoli, Pierre, Songsasen, Nucharin, and Wildt, David E. 2010. "Protecting and Extending Fertility for Females of Wild and Endangered Mammals." In Oncofertility. 87–100. Springer US. In Cancer Treatment and Research (vol. 156). 2010
• Songsasen, Nucharin and Comizzoli, Pierre. 2009. "A historic overview of embryos and oocyte preservation in the world of mammalian in vitro fertilization and biotechnology." In Preservation of Human Oocytes. Borini, A. and Coticchio, G., editors. 1–11. London: Informa Healthcare. 2009

Dataset

• Moraes, Rosana, Leimgruber, Peter, Stabach, Jared, Laske, Timothy G., and Songsasen, Nucharin. 2023. [Dataset] Heart rate monitoring of captive scimitar-horned oryx. Distributed by Washington, DC: Smithsonian National Zoo and Conservation Biology Institute. https://doi.org/10.25573/DATA.21391068.V3. 2023

Review

• Songsasen, Nucharin and Nagashima, Jennifer. 2020. [Book review] "Intraovarian regulation of folliculogenesis in the dog: A review." Reproduction in Domestic Animals, 55, (S2), 66–73. https://doi.org/10.1111/rda.13657. 2020