Ankfn1-mutant vestibular defects require loss of both ancestral and derived paralogs for penetrance in zebrafish

How and to what degree gene duplication events create regulatory innovation, redundancy, or neofunctionalization remain important questions in animal evolution and comparative genetics. Ankfn1 genes are single copy in most invertebrates, partially duplicated in jawed vertebrates, and only the derived copy retained in most mammals. Null mutations in the single mouse homolog have vestibular and neurological abnormalities. Null mutation of the single Drosophila homolog is typically lethal with severe sensorimotor deficits in rare survivors. The functions and potential redundancy of paralogs in species with two copies is not known. Here we define a vestibular role for Ankfn1 homologs in zebrafish based on simultaneous disruption of each locus. Zebrafish with both paralogs disrupted showed vestibular defects and early lethality from swim bladder inflation failure. One intact copy at either locus was sufficient to prevent major phenotypes. Our results show that vertebrate Ankfn1 genes are required for vestibular-related functions, with at least partial redundancy between ancestral and derived paralogs.

Ankfn1 vestibular defects in zebrafish require mutations in both ancestral and derived paralogs.

How and to what degree gene duplication events create regulatory innovation, redundancy, or neofunctionalization remain important questions in animal evolution and comparative genetics. Ankfn1 genes are single copy in most invertebrates, partially duplicated in jawed vertebrates, and only the derived copy retained in most mammals. Null mutations in the single mouse homolog have vestibular and neurological abnormalities. Null mutation of the single Drosophila homolog is typically lethal with severe sensorimotor deficits in rare survivors. The functions and potential redundancy of paralogs in species with two copies is not known. Here we define a vestibular role for Ankfn1 homologs in zebrafish based on simultaneous disruption of each locus. Zebrafish with both paralogs disrupted showed vestibular defects and early lethality from swim bladder inflation failure. One intact copy at either locus was sufficient to prevent major phenotypes. Our results show that vertebrate Ankfn1 genes are required for vestibular-related functions, with at least partial redundancy between ancestral and derived paralogs.

Comparative Genetics Using Three mtDNA Markers in Aedes aegypti (Linnaeus) Populations from Four Municipalities in the Satate of Mato Grosso, Brazil.

Aedes aegypti mosquito has spread throughout the tropical and subtropical world and is currently the primary species responsible for transmitting dengue, urban yellow fever, Chikungunya, and Zika virus. This study aimed to investigate the inter- and intrapopulational genetic variability of Aedes aegypti through mitochondrial DNA, COI, ND4, and ND5 molecular markers in four municipalities in Mato Grosso. We used the Geneious software to build dendrograms for differentiating populations from each municipality. The interpopulational genetic distance obtained from sequence analysis showed a difference within populations through groups' formation in the ordering. Besides, we identified a difference in the interindividual genetic distance values, notably for the ND5 gene from the populations captured in the four municipalities. We recorded the smallest interindividual genetic distance within populations for populations from Chapada dos Guimarães. Extrinsic factors, including breeding habitat removal, can contribute to decreasing variability. Consequently, the dendrogram showed some similarities. Ovitrap monitoring, vector elimination, and genetic flow investigation stimulate actions to prevent transmitted diseases and support essential effective measures to control and fight Ae. aegypti.

A phylogenetic framework of the legume genusAeschynomenefor comparative genetic analysis of the Nod-dependent and Nod-independent symbioses

SUMMARYSomeAeschynomenelegume species have the property of being nodulated by photosyntheticBradyrhizobiumlacking thenodABCgenes. Knowledge of this unique Nod (factor)-independent symbiosis has been gained from the modelA. eveniabut our understanding remains limited due to the lack of comparative genetics with related taxa using a Nod-dependent process.To fill this gap, this study significantly broadened previous taxon sampling, including in allied genera, to construct a comprehensive phylogeny. This backbone tree was matched with data on chromosome number, genome size, low-copy nuclear genes and strengthened by nodulation tests and a comparison of the diploid species.The phylogeny delineated five main lineages that all contained diploid species while polyploid groups were clustered in a polytomy and were found to originate from a single paleo-allopolyploid event. In addition, new nodulation behaviours were revealed and Nod-dependent diploid species were shown to be tractable.The extended knowledge of the genetics and biology of the different lineages in the legume genusAeschynomeneprovides a solid research framework. Notably, it enabled the identification ofA. americanaandA. patulaas the most suitable species to undertake a comparative genetic study of the Nod-independent and Nod-dependent symbioses.