Publications by authors named "Villagran-SantaCruz Maricela"

Article Synopsis
  • Extraembryonic membranes protect and nourish developing embryos, and studying them helps us understand the evolution of eggs and live births in animals.
  • In the viviparous snake Conopsis lineata, researchers describe the structure and types of placentation during various gestation stages using microscopy.
  • By late gestation, a highly vascularized allantois forms a connection with the placenta, revealing that the evolution of these structures shows similarities with other squamate species, whether they lay eggs or give birth to live young.
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Viviparity is the reproductive pattern in which females gestate eggs within their reproductive tract to complete their development and give birth to live offspring. Within extant sauropsids, only the Squamata (e.g.

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Primordial germ cells (PGCs) are highly specialized cells that play a relevant role in the maintenance and evolution of the species, since they create new combinations of genetic information between the organisms. Amphibians are a class of amniote vertebrates that are divided into three subclasses, the anurans (frogs and toads), the urodeles (salamanders and newts), and the gymnophiones (caecilians). The study of PGCs in amphibians has been addressed in more detail in anurans while little is known about the biology of this cell lineage in urodeles.

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Oviparous species of exhibit either seasonal or continuous spermatogenesis and populations from high-elevation show a seasonal pattern known as spring reproductive activity. We studied the spermatogenic cycle of a high-elevation (2700 m) population of endemic oviparous lizard, , that resided south of México, D.F.

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Several recent studies have mapped out the characters of spermiogenesis within several species of squamates. Many of these data have shown both conserved and possibly apomorphic morphological traits that could be important in future phylogenetic analysis within Reptilia. There, however, has not been a recent study that compares spermiogenesis and its similarities or differences between two species of reptile that reside in the same genus.

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