Parthenogenetic Lizards

The bisexual brain: sex behavior differences and sex differences in parthenogenetic and sexual lizards.

The parthenogenetic lizard Cnemidophorus uniparens alternates in the display of male-like and female-like sexual behavior, providing a unique opportunity for determining the neuronal circuits subserving gender-typical sexual behavior within a single sex. Here we report a 6-fold greater [14C]2-fluoro-2-deoxyglucose uptake in the medial preoptic area of C. uniparens displaying male-like behavior ...

Chromosome inheritance in parthenogenetic lizards and evolution of allopolyploidy in reptiles

ABOUT one percent of the 3,000 species of lizards in the world have all-female populations in which reproduction seems to be by true parthenogenesis (as opposed to gynogenesis or hybridogenesis). For some species, no males have ever been found at any localities. For a few species, all-female populations occur at some localities, bisexual populations at others. (In unisexual populations all norm...

Widespread failure to complete meiosis does not impair fecundity in parthenogenetic whiptail lizards

Parthenogenetic species of whiptail lizards in the genus Aspidoscelis constitute a striking example of speciation by hybridization, in which first-generation hybrids instantly attain reproductive isolation and procreate as clonal all-female lineages. Production of eggs containing a full complement of chromosomes in the absence of fertilization involves genome duplication prior to the meiotic di...

Differential effects of testosterone and progesterone on the activation and retention of courtship behavior in sexual and parthenogenetic whiptail lizards.

Both testosterone (T) and progesterone (P) facilitate the expression of male-typical sexual behavior in a variety of animals, including rodents and lizards. In two species of whiptail lizards, Cnemidophorus inornatus and C. uniparens, both hormones elicit the full repertoire of courtship behavior. However, the relative efficacy of the two hormones is unknown. In Experiments 1 and 2 we assessed ...

Sex of Parthenogenetic Frogs