DNA marking of the rate of maturation of gonads in female sterlet x beluga (A. ruthenus x H. huso) hybrid under conditions of recirculation systems

To create a theoretical basis for the development of new technologies for the formation of highly productive sturgeon herds, work has begun on conducting research on DNA - markers associated with economically useful traits. At the first stage of the work, polymorphic regions of the mitochondrial DNA (mtDNA) D-loop were investigated in order to search for promising molecular genetic markers associated with the production properties of sturgeon hybrids. Along with point polymorphisms in mtDNA hybrids, variability in the length of the D-loop was observed, as well as the presence of heteroplasmy in length. The length variability of the D-loop is due to the presence of tandem repeating units in multiples of 80 base pairs (bp). Using Fisher’s exact test, it was shown that the proportion of individuals with four tandem repeating units of 80 bp eachsignificantly higher (p = 0.030) in the group of highly productive hybrids. The obtained data suggest that such a trait as the accelerated maturation of female hybrids (A. ruthenus x H. huso) grown in a closed water supply can be associated with the mitochondrial DNA haplotype, in the D-loop of which there are fourrepeating units.

First Record of a Novel Mitochondrial DNA Haplotype of a Marble Trout Lineage of Salmo Trutta in Turkey

A new record of a marble trout mtDNA haplotype known to be restricted to Adriatic basin (called marmoratus lineage within Salmo trutta complex) has been reported from Eşen Stream in the Aegean Sea basin of southeastern Turkey, based on sequence data of the mitochondrial DNA control region. The results of this study showed a single unique haplotype from this population, called MATR1. Phylogenetic analyses of this haplotype along with other haplotypes belonging to different mitochondrial DNA lineages of the S. trutta complex confirmed the existence of the marmoratus lineage in Turkey, suggesting a possible river capture between the Adriatic and Aegean Sea basins until the last (Würmian) marine regression.

Mitochondrial DNA Haplotypes Influence Energy Metabolism across Chicken Transmitochondrial Cybrids

The association between mitochondrial DNA haplotype and productive performances has been widely reported in chicken breeds. However, there has not been physiological evidence of this seen previously. In this study, chicken transmitochondrial cells were generated using the nucleus of the DF-1 cell line and mitochondria of primary cell lines derived from two native chicken breeds, Tibetan chicken and Shouguang chicken. Generally, Tibetan chicken primary cells showed a stronger metabolic capacity than Shouguang chicken primary cells. However, the Tibetan chicken cybrids had a dramatic drop in relative mtDNA copies and oxygen consumption. Higher rates of oxygen consumption (OCR) and expression levels of mitochondrial biogenesis and fusion genes were observed in Shouguang chicken cybrids, potentially reflecting that the mitochondrial DNA haplotype of Shouguang chicken had better coordination with the DF-1 nucleus than others. Meanwhile, mitonuclear incompatibility occurred in Tibetan chicken cybrids. The results demonstrate functional differences among mitochondrial DNA haplotypes and may shed light on the interaction between the mitochondria and nucleus in Gallus gallus domesticus.

Diet and mitochondrial DNA haplotype of a sperm whale (Physeter macrocephalus) found dead off Jurong Island, Singapore

Despite numerous studies across the large geographic range of the sperm whale (Physeter macrocephalus), little is known about the diet and mitochondrial DNA haplotypes of this strongly female philopatric species in waters off Southeast Asia. A female sperm whale found dead in Singapore waters provided the opportunity to study her diet and mitochondrial DNA haplotype. Here we report on the identification of stomach contents and mitochondrial DNA haplotype of this individual, and we include coastal hydrodynamic modelling to determine the possible geographic origin of the whale. At least 28 species of prey were eaten by this adult female whale, most of which were cephalopods. The mesopelagic squids Taonius pavo, Histioteuthis pacifica, Chiroteuthis imperator,and Ancistrocheirus lesueurii made up over 65% of the whale’s stomach contents. Plastic debris was also found in the whale’s stomach. Based on the diet, genetics, and coastal hydrodynamic modelling that suggest an easterly drift of the whale carcass over several days, the dead sperm whale in Singapore probably originated from a pod in the Southern Indian Ocean. This study provides an increase in the understanding the diet and natural history of the sperm whale in Southeast Asia. The combined analyses of stomach contents, DNA, and hydrodynamic modeling could provide a context to future studies on the sperm whale strandings, and have broader applicability for other marine mammals in the region.