21 research outputs found
Avian W and mammalian Y chromosomes convergently retained dosage-sensitive regulators
After birds diverged from mammals, different ancestral autosomes evolved into sex chromosomes in each lineage. In birds, females are ZW and males are ZZ, but in mammals females are XX and males are XY. We sequenced the chicken W chromosome, compared its gene content with our reconstruction of the ancestral autosomes, and followed the evolutionary trajectory of ancestral W-linked genes across birds. Avian W chromosomes evolved in parallel with mammalian Y chromosomes, preserving ancestral genes through selection to maintain the dosage of broadly expressed regulators of key cellular processes. We propose that, like the human Y chromosome, the chicken W chromosome is essential for embryonic viability of the heterogametic sex. Unlike other sequenced sex chromosomes, the chicken W chromosome did not acquire and amplify genes specifically expressed in reproductive tissues. We speculate that the pressures that drive the acquisition of reproduction-related genes on sex chromosomes may be specific to the male germ line
TWO LOBELIA (CAMPANULACEAE) GYPSOPHILES FROM NUEVO LE 3N, M\uc9XICO
Volume: 13Start Page: 141End Page: 14
SYSTEMATICS OF SALVIA PACHYPHYLLA (LAMIACEAE)
Volume: 53Start Page: 11End Page: 2
Cladistics, bruchids and host plants: evolucionary interactions in Amblycerus (Coleoptera: Bruchidae)
A preliminary cladistic analysis of forty species of Amblycerus Thunberg is presented based on 29 morphological characters. The analysis generated four equally parsimonious trees of 60 steps in length with a consistency index of 0.63 and a retention index of 0.88. By replacing host families by each species of Amblycerus on the cladogram, an approximation of macroevolution into host taxa was formulated. These bruchids appear to have moved from the plant family Fabaceae into 12 other plant families, with many species into the families Sterculiaceae and Boraginaceae. Various factors including oviposition behavior are cited for some host shifts. Plant chemistry is especially important but we only have correlative data to support these conclusions. To us, it appears that the most parsimonious explanation for the host shifts that we observed was by macroevolution during enhanced rates of bruchid diversification in the Recent epoch.Se presenta una análisis cladístico preliminar para 40 especies de Amblycerus Thunberg basado en 29 caracteres morfológicos. Se generaron cuatro árboles igualmente parsimoniosos de 60 pasos de longitud, con una consistencia de 0.63 y un índice de retención de 0.88. Remplazando en el cladograma cada una de las especies de Amblycerus por la familia de la planta huésped, fue posible formular una aproximación de la macroevolución en los taxones de los huéspedes. Al parecer estos brúquidos se han movido de la familia de plantas Fabaceae a 12 familias de otras plantas, principalmente Sterculiaceae y Boraginaceae. Varios factores, incluyendo el comportamiento de oviposición, se han citado para explicar algunos de los cambios de huésped. La bioquímica de la planta es especialmente importante, aunque solamente contamos con datos correlativos para soportar estas conclusiones. Para nosotros, la explicación más parsimoniosa sobre los cambios de huésped que observamos es por macroevolución durante ciertos periodos en la diversificación de los brúquidos en la época reciente
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Recent Advances in Research on Hoarding
Purpose of reviewThe purpose of the following paper is to review recent literature trends and findings in hoarding disorder (HD). Our goal is to highlight recent research on etiology, associated features, and empirically based treatments.Recent findingsRecent literature has added support for cognitive differences as a risk factor for HD; however, there is evidence that individuals with HD may overestimate their level of cognitive impairment. Several associated features have been highlighted in recent studies, including emotion regulation, intolerance of uncertainty and distress intolerance, and attachment. Finally, several psychotherapeutic treatments for hoarding have been recently validated, including group-based therapy and treatments using the cognitive-behavioral model. Although recent research demonstrates that hoarding can be effectively treated with available psychotherapeutic modalities, the effectiveness of current treatments is not as robust as that for other psychiatric disorders and more work is needed in treatment precision
Alignment_Campanulaceae_all_genes_dataset
Alignment_Campanulaceae_all_genes_datase
PollenPresent_Invagination_Matrix
PollenPresent_Invagination_Matri
PollenPresent_StylarGrowth_Matrix
PollenPresent_StylarGrowth_Matri
PollenPresent_AntherArrangement_Matrix
PollenPresent_AntherArrangement_Matri