Here, we compare male and females karyotypes of the pink-tailed w

Here, we compare male and females karyotypes of the pink-tailed worm-lizard (Aprasia parapulchella), a small legless lizard belonging to the endemic Australian family Pygopodidae.

Results: We applied comparative genomic hybridization to reveal an XX/XY sex chromosome system in which the Y chromosome is highly selleck compound differentiated from the X in both gross morphology and DNA sequence. In addition, FISH mapping has revealed that two microsatellite repeat motifs, (AGAT)n and (AC)n, have been amplified multiple times on the Y chromosome.

Conclusion: XY karyotypes are found in other pygopodids (Delma inornata and Lialis burtonis), suggesting that the common ancestor of Pygopodidae also had XY

Smad inhibitor sex chromosomes. However, the morphology and size of the Y chromosomes are different among the three species, suggesting that the processes underlying the evolution of sex chromosomes in the Pygopodidae involved chromosome rearrangements and accumulation and amplification of repeats.”
“Humans, like other animals, are exposed to a continuous stream of signals, which are dynamic, multimodal, extended, and time varying

in nature. This complex input space must be transduced and sampled by our sensory systems and transmitted to the brain where it can guide the selection of appropriate actions. To simplify this process, it’s been suggested that the brain exploits statistical regularities in the stimulus space. Tests of this idea have largely been

confined to unimodal signals and natural scenes. One important class of multisensory signals for which a quantitative input space characterization is unavailable is human speech. We do not understand what signals our brain has to actively piece together from an audiovisual speech stream to arrive at a percept versus what is already embedded in the signal structure of the stream itself. In essence, we do not have a clear understanding of the natural statistics of audiovisual speech. In the present study, we identified the following major statistical features of audiovisual speech. First, we observed robust correlations and close temporal correspondence between the area of the mouth opening and the acoustic envelope. MLN4924 Second, we found the strongest correlation between the area of the mouth opening and vocal tract resonances. Third, we observed that both area of the mouth opening and the voice envelope are temporally modulated in the 2-7 Hz frequency range. Finally, we show that the timing of mouth movements relative to the onset of the voice is consistently between 100 and 300 ms. We interpret these data in the context of recent neural theories of speech which suggest that speech communication is a reciprocally coupled, multisensory event, whereby the outputs of the signaler are matched to the neural processes of the receiver.

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