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31.
Complex selection on a regulator of social cognition: Evidence of balancing selection,regulatory interactions and population differentiation in the prairie vole Avpr1a locus
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Alejandro Berrio Rafael F. Guerrero Galina V. Aglyamova Mariam Okhovat Mikhail V. Matz Steven M. Phelps 《Molecular ecology》2018,27(2):419-431
Adaptive variation in social behaviour depends upon standing genetic variation, but we know little about how evolutionary forces shape genetic diversity relevant to brain and behaviour. In prairie voles (Microtus ochrogaster), variants at the Avpr1a locus predict expression of the vasopressin 1a receptor in the retrosplenial cortex (RSC), a brain region that mediates spatial and contextual memory; cortical V1aR abundance in turn predicts diversity in space use and sexual fidelity in the field. To examine the potential contributions of adaptive and neutral forces to variation at the Avpr1a locus, we explore sequence diversity at the Avpr1a locus and throughout the genome in two populations of wild prairie voles. First, we refine results demonstrating balancing selection at the locus by comparing the frequency spectrum of variants at the locus to a random sample of the genome. Next, we find that the four single nucleotide polymorphisms that predict high V1aR expression in the RSC are in stronger linkage disequilibrium than expected by chance despite high recombination among intervening variants, suggesting that epistatic selection maintains their association. Analysis of population structure and a haplotype network for two populations revealed that this excessive LD was unlikely to be due to admixture alone. Furthermore, the two populations differed considerably in the region shown to be a regulator of V1aR expression despite the extremely low levels of genomewide genetic differentiation. Together, our data suggest that complex selection on Avpr1a locus favours specific combinations of regulatory polymorphisms, maintains the resulting alleles at population‐specific frequencies, and may contribute to unique patterns of spatial cognition and sexual fidelity among populations. 相似文献
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Molecular evolution of mitochondrial 12S RNA and cytochrome b sequences in the pantherine lineage of Felidae 总被引:4,自引:2,他引:2
DNA sequence comparisons of two mitochondrial DNA genes were used to infer
phylogenetic relationships among 17 Felidae species, notably 15 in the
previously described pantherine lineage. The polymerase chain reaction
(PCR) was used to generate sequences of 358 base pairs of the mitochondrial
12S RNA gene and 289 base pairs of the cytochrome b protein coding gene.
DNA sequences were compared within and between 17 felid and five nonfelid
carnivore species. Evolutionary trees were constructed using phenetic,
cladistic, and maximum likelihood algorithms. The combined results
suggested several phylogenetic relationships including (1) the recognition
of a recently evolved monophyletic genus Panthera consisting of Panthera
leo, P. pardus, P. onca, P. uncia, P. tigris, and Neofelis nebulosa; (2)
the recent common ancestry of Acinonyx jubatus, the African cheetah, and
Puma concolor, the American puma; and (3) two golden cat species, Profelis
temmincki and Profelis aurata, are not sister species, and the latter is
strongly associated with Caracal caracal. These data add to the growing
database of vertebrate mtDNA sequences and, given the relatively recent
divergence among the felids represented here (1-10 Myr), allow 12S and
cytochrome b sequence evolution to be addressed over a time scale different
from those addressed in most work on vertebrate mtDNA.
相似文献
34.
Sea urchin Hox genes: insights into the ancestral Hox cluster 总被引:3,自引:0,他引:3
We describe the Hox cluster in the radially symmetric sea urchin and
compare our findings to what is known from clusters in bilaterally
symmetric animals. Several Hox genes from the direct-developing sea urchin
Heliocidaris erythrogramma are described. CHEF gel analysis shows that the
Hox genes are clustered on a < or = 300 kilobase (kb) fragment of DNA,
and only a single cluster is present, as in lower chordates and other
nonvertebrate metazoans. Phylogenetic analyses of sea urchin, amphioxus,
Drosophila, and selected vertebrate Hox genes confirm that the H.
erythrogramma genes, and others previously cloned from other sea urchins,
belong to anterior, central, and posterior groups. Despite their radial
body plan and lack of cephalization, echinoderms retain at least one of the
anterior group Hox genes, an orthologue of Hox3. The structure of the
echinoderm Hox cluster suggests that the ancestral deuterostome had a Hox
cluster more similar to the current chordate cluster than was expected Sea
urchins have at least three Abd-B type genes, suggesting that Abd-B
expansion began before the radiation of deuterostomes.
相似文献
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Pseudomonas aeruginosa diaminopimelate decarboxylase: evolutionary relationship with other amino acid decarboxylases 总被引:1,自引:0,他引:1
Martin C; Cami B; Yeh P; Stragier P; Parsot C; Patte JC 《Molecular biology and evolution》1988,5(5):549-559
The lysA gene encodes meso-diaminopimelate (DAP) decarboxylase
(E.C.4.1.1.20), the last enzyme of the lysine biosynthetic pathway in
bacteria. We have determined the nucleotide sequence of the lysA gene from
Pseudomonas aeruginosa. Comparison of the deduced amino acid sequence of
the lysA gene product revealed extensive similarity with the sequences of
the functionally equivalent enzymes from Escherichia coli and
Corynebacterium glutamicum. Even though both P. aeruginosa and E. coli are
Gram-negative bacteria, sequence comparisons indicate a greater similarity
between enzymes of P. aeruginosa and the Gram- positive bacterium C.
glutamicum than between those of P. aeruginosa and E. coli enzymes.
Comparison of DAP decarboxylase with protein sequences present in data
bases revealed that bacterial DAP decarboxylases are homologous to mouse
(Mus musculus) ornithine decarboxylase (E.C.4.1.1.17), the key enzyme in
polyamine biosynthesis in mammals. On the other hand, no similarity was
detected between DAP decarboxylases and other bacterial amino acid
decarboxylases.
相似文献
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