Title

Does Hybridization Affect Placental Morphology in Dwarf Hamsters?

Presentation Type

Poster

Abstract

New species form through a process called speciation. When a barrier to gene flow arises between two populations they begin to diverge. A common outcome of genetic divergence is reproductive isolation, a common example of which is hybrid inviability. This study was aimed at characterizing a subtle aspect of hybrid inviability that occurs during embryonic development. In mammals, a crucial part of the early stages of development is the transfer of nutrients directly from the mother to the embryo through a complex layered tissue called the placenta. Disruptions of placental form and function may result in abnormal growth or even developmental failure. Hybrids between two hamster species, Phodopus sungorus and P. campbelli, exhibit abnormal embryonic growth. When P. campbelli is the mother, the hybrids are smaller than both parental species, and when P. sungorus is the mother, the hybrids are so extremely overgrown it results in maternal death during birth. One possible contributing factor to these developmental problems of the hybrids is abnormal placental morphology. I used histological methods to obtain placental sections from both pure species and each reciprocal hybrid. Image analysis of these sections revealed no abnormalities of placenta layers in the male hybrids compared with the pure species. Qualitatively, placentas from female hybrids seem to show abnormal composition and morphology. These placental defects are likely to result in a reduction of placental function, hinder proper embryonic development, and contribute to the isolation of these closely related two species.

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Apr 12th, 11:00 AM Apr 12th, 12:00 PM

Does Hybridization Affect Placental Morphology in Dwarf Hamsters?

UC Ballroom

New species form through a process called speciation. When a barrier to gene flow arises between two populations they begin to diverge. A common outcome of genetic divergence is reproductive isolation, a common example of which is hybrid inviability. This study was aimed at characterizing a subtle aspect of hybrid inviability that occurs during embryonic development. In mammals, a crucial part of the early stages of development is the transfer of nutrients directly from the mother to the embryo through a complex layered tissue called the placenta. Disruptions of placental form and function may result in abnormal growth or even developmental failure. Hybrids between two hamster species, Phodopus sungorus and P. campbelli, exhibit abnormal embryonic growth. When P. campbelli is the mother, the hybrids are smaller than both parental species, and when P. sungorus is the mother, the hybrids are so extremely overgrown it results in maternal death during birth. One possible contributing factor to these developmental problems of the hybrids is abnormal placental morphology. I used histological methods to obtain placental sections from both pure species and each reciprocal hybrid. Image analysis of these sections revealed no abnormalities of placenta layers in the male hybrids compared with the pure species. Qualitatively, placentas from female hybrids seem to show abnormal composition and morphology. These placental defects are likely to result in a reduction of placental function, hinder proper embryonic development, and contribute to the isolation of these closely related two species.