Mitochondrial heteroplasmy in an avian hybrid form (Passer italiae: Aves, Passeriformes)

Mitochondrial heteroplasmy is the result from biparental transmission of mitochondrial DNA (mtDNA) to the offspring. In such rare cases, maternal and paternal mtDNA is present in the same individual. Though recent studies suggested that mtDNA heteroplasmy might be more common than previously anticipated, that phenomenon is still poorly documented and was mostly detected in case studies on hybrid populations. The Italian sparrow, Passer italiae is a homoploid hybrid form that occurs all across the Italian Peninsula mostly under strict absence of either of its parent species, the house sparrow (P. domesticus) and the Spanish sparrow (P. hispaniolensis). In this study, we document a new case of mitochondrial heteroplasmy from two island populations of P. italiae (Ustica and Lipari). Our analysis was based on the mitochondrial NADH dehydrogenase subunit 2 (ND2) that allows for a clear distinction between mitochondrial lineages of the two parental species. We amplified and sequenced the mitochondrial ND2 gene with specifically designed primer combinations for each of the two parental species. In two of our study populations, a single individual carried two different ND2 haplotypes from each of the two parental lineages. These findings contribute to current knowledge on the still poorly documented phenomenon of paternal leakage in vertebrates

Development of the Drosophila-Melanogaster Caudal Segments Involves Suppression of the Ventral Regions of A8, A9 and A10

Whereas the segmental organization of the thorax and anterior abdomen is morphologically delineated in both the Drosophila larva and adult, segments in the head and caudal regions lack such well-defined boundaries. Consequently, the organization of these regions has been difficult to decipher. In this study, transformations caused by the bithorax-complex homeotic mutants 48, M3, Ultraabdominal-1 (Uab1) and tumorous-head-3 (tuh-3), as well as the patterns of engrailed gene expression have been analyzed to investigate the segmental organization of the caudal segments. A special emphasis was placed on sense organs appearing in abdominal segments 8, 9 and 10 (A8-A10): We find that: (1) transformations in the caudal segments obey parasegmental borders; (2) the sense organs on A8, A9, and A10 are probably homologous to the pits and hairs in anterior A1-A7; (3) except for the larval anal tuft and the anterior side of A8, all structures in larval segments A8, A9 and A10 are dorsal/lateral in origin; and (4) dorsalization of embryonic A8 and A9 cells leaves space ventrally for A10, as it follows the contracting ventral nervous system during the embryological process of germ band contraction

Pilot biodiversity assessment of the Hkakabo Razi passerine avifauna in northern Myanmar – implications for conservation from molecular genetics

The Hkakabo Razi region located in northern Myanmar is an Important Bird Area and part of the Eastern Himalayan Biodiversity Hotspot. Within the framework of the World Heritage Convention to enlist the site under criterion (ix) and (x), we conducted a biodiversity assessment for passerine birds using DNA barcoding and other molecular markers. Of the 441 bird species recorded, we chose 16 target species for a comparative phylogeographic study. Genetic analysis was performed for a larger number of species and helped identifying misidentified species. We found phylogeographic structure in all but one of the 16 study species. In 13 species, populations from northern Myanmar were genetically distinctive and local mitochondrial lineages differed from those found in adjacent regions by 3.9– 9.9% uncorrected genetic distances (cytochrome-b). Since the genetic distinctiveness of study populations will be corroborated by further differences in morphology and song as in other South-East Asian passerines, many of them will be candidates for taxonomic splits, or in case an older taxon name is not available, for the scientific description of new taxa. Considering the short time frame of our study we predict that a great part of undetected faunal diversity in the Hkakabo Razi region will be discovered