• Altered gonadal expression of TGF-beta superfamily signaling factors in environmental contaminant-exposed juvenile alligators

      Moore, B.C.; Milnes, Matthew R.; Kohno, S.; Katsu, Y.; Iguchi, T. (2011)
      Environmental contaminant exposure can influence gonadal steroid signaling milieus; however, little research has investigated the vulnerability of non-steroidal signaling pathways in the gonads. Here we use American alligators (Alligator mississippiensis) hatched from field-collected eggs to analyze gonadal mRNA transcript levels of the activin–inhibin–follistatin gene expression network and growth differentiation factor 9....
    • An interdisciplinary systems approach to study sperm physiology and evolution

      Shi, L.Z.; Nascimento, J.; Botvinick, E.; Durrant, Barbara S.; Berns, M.W. (2011)
      Optical trapping is a noninvasive biophotonic tool that has been developed to study the physiological and biomechanical properties of cells…. A real‐time automated tracking and trapping system (RATTS) is described that provides a remote user‐friendly robotic interface…. This combination of photonic physical and engineering tools has been used to examine the evolutionary effect of sperm competition in primates….
    • Characterization of cultured adult Corturnix japonica testicular germ stem cells using seven stem cell markers.

      Jensen, Thomas; Poling, Matthew; Charter, Suellen; Durrant, Barbara S.; (2010)
      ...The large avian oocyte and the inability to consistently superovulate birds make techniques such as cloning and oocyte cryopreservation unlikely tools for avian conservation. Instead, the use of domestic birds as hosts to produce sperm of exotic species for use in artificial insemination may be a practical approach to conserve avian germplasm....
    • Hormones and reproductive cycles in Crocodilians

      Milnes, Matthew R.; Norris, D.O.; Lopez, K.H. (ElsevierSan Diego, CA, 2011)
      During embryonic development, hormonal influence upon sexual differentiation in crocodilians begins and continues for years until sexual maturation is attained. Shortly after sex determination, estrogen production in the embryonic ovary increases and promotes proliferation of the Müsllerian ducts, whereas the testis produces anti-Müllerian hormone, which results in its regression....
    • Influences of sex, incubation temperature, and environmental quality on gonadal estrogen and androgen receptor messenger RNA expression in juvenile American alligators (Alligator mississippiensis)

      Moore, B.C.; Milnes, Mathew R.; Kohno, S.; Katsu, Y.; Iguchi, T.; LJ, Guilette, Jr; (2010)
      ...We have shown previously that gonads from wild-caught juvenile alligators express greater levels of estrogen receptor 1 (ESR1) than estrogen receptor 2 (ESR2).... These findings demonstrate that the mRNA expression of receptors required for steroid hormone signaling are modified by exposure to environmental factors, including temperature and contaminants.
    • Scent-marking behavior by female sloth bears during estrus

      Khadpekar, Yaduraj; Whiteman, John P.; Durrant, Barbara S.; Owen, Megan A.; Prakash, Sant (2021)
      … Important aspects of sloth bear biology and ecology, such as reproductive physiology and behavior, are largely unknown. Increased scent-marking by anogenital rubbing during breeding season has been recorded in other bear species. We studied the genital rubbing behavior of 37 captive female sloth bears (2–18 yr of age) at the Agra Bear Rescue Facility, India, for 4 breeding seasons over a period of 3.5 years (1 Jun 2015 to 31 Dec 2018)….
    • The acute phase protein ceruloplasmin as a non-invasive marker of pseudopregnancy, pregnancy, and pregnancy loss in the giant panda

      Willis, Erin L.; Kersey, David C.; Durrant, Barbara S.; Kouba, Andrew J. (2011)
      After ovulation, non-pregnant female giant pandas experience pseudopregnancy. During pseudopregnancy, non-pregnant females exhibit physiological and behavioral changes similar to pregnancy. Monitoring hormonal patterns that are usually different in pregnant mammals are not effective at determining pregnancy status in many animals that undergo pseudopregnancy, including the giant panda. Therefore, a physiological test to distinguish between pregnancy and pseudopregnancy in pandas has eluded scientists for decades. We examined other potential markers of pregnancy and found that activity of the acute phase protein ceruloplasmin increases in urine of giant pandas in response to pregnancy. Results indicate that in term pregnancies, levels of active urinary ceruloplasmin were elevated the first week of pregnancy and remain elevated until 20–24 days prior to parturition, while no increase was observed during the luteal phase in known pseudopregnancies. Active ceruloplasmin also increased during ultrasound-confirmed lost pregnancies; however, the pattern was different compared to term pregnancies, particularly during the late luteal phase. In four out of the five additional reproductive cycles included in the current study where females were bred but no birth occurred, active ceruloplasmin in urine increased during the luteal phase. Similar to the known lost pregnancies, the temporal pattern of change in urinary ceruloplasmin during the luteal phase deviated from the term pregnancies suggesting that these cycles may have also been lost pregnancies. Among giant pandas in captivity, it has been presumed that there is a high rate of pregnancy loss and our results are the first to provide evidence supporting this notion.