Polymorphisms in DMRT1 coding and promoter regions are probably not causative for swine sex reversal (XX, SRY-negative) syndrome

SRY-negative XX sex reversal is an inherited or sporadically occurring disorder, where testis development appears in the absence of the SRY gene. Although the molecular background of this intersexuality syndrome in pigs is unknown, it was proposed that familial cases might be inherited as a single autosomal recessive trait. Because DMRT1 (Doublesex and Mab-3 related transcription factor 1) is an autosomal locus in pig (SSC1q21), shows sexually dimorphic expression in swine gonads and has strong significance in vertebrate testis development, the molecular analysis of this gene was performed in previously reported three intersexes (38,XX, SRY-negative), the progeny of a single boar from a Polish farm. The first two exons encoding functional DM (double sex and mab-3) domain and the promoter region (the 5'flanking sequence) (altogether 3894 bp) were sequenced and compared with male and female control pigs (n = 16) and with publicly available sequences. Three different polymorphisms were found in the coding region, one Indel type polymorphism (DNA 142_144indelAGC) causing a deletion of an amino acid (protein S47_G48indelS) and two silent SNPs (DNA G432A and G492A). The promoter region seems to be highly polymorphic, since 17 SNPs and 5 indels were detected. However, the sequences of control males and females were concordant with those of the intersexes. These results indicate that DMRT1 is an unlikely candidate gene for SRY-negative XX sex reversal in pig

Tests of multiple molecular markers for the identification of Great Spotted and Syrian Woodpeckers and their hybrids

Great Spotted and Syrian Woodpeckers (Dendrocopos major and D. syriacus) are known to hybridize in nature; however, the extent of this phenomenon is not known due to difficulties in hybrid detection based on plumage analyses. Here, we tested five markers (one mitochondrial and four nuclear) and a set of six microsatellite loci for the identification of these two Woodpeckers and their hybrids. Sequencing of DNA from 26 individuals of both Woodpeckers from different parts of their ranges: one allopatric (D. major; Norway) and two sympatric (Poland and Bulgaria) showed that both species can be clearly separated based on all sequence markers. The highest number of fixed nucleotide sites were found in the mtDNA control region and intron 5 of the transforming growth factor. Analyses of microsatellite data distinguished the two species, but all loci showed a large number of common alleles and their utility in identifying hybrids is therefore doubtful. According to the DNA sequence analyses, 2 out of 18 specimens within the sympatric range in Poland were identified as possible hybrids, most probably paternal backcrosses. Moreover, both hybrids are from synantropic populations (settled in cities), whereas none of the D. major sampled in forests and in its allopatric range (Norway) showed signs of an intermixed genotype. Further research on hybridization and introgression in woodpeckers is undoubtedly needed and could be useful for understanding ecological and ethological interactions among these species, particularly for D. syriacus, which is relatively rare in Europe

Reconstructed historical distribution and phylogeography unravels non-steppic origin of Caucasotachea vindobonensis (Gastropoda: Helicidae)

Existing data on the phylogeography of European taxa of steppic provenance suggests that species were widely distributed during glacial periods but underwent range contraction and fragmentation during interglacials into “warm-stage refugia.” Among the steppe-related invertebrates that have been examined, the majority has been insects, but data on the phylogeography of snails is wholly missing. To begin to fill this gap, phylogeographic and niche modeling studies on the presumed steppic snail Caucasotachea vindobonensis were conducted. Surprisingly, reconstruction of ancestral areas suggests that extant C. vindobonensis probably originated in the Balkans and survived there during the Late Pleistocene glaciations, with a more recent colonization of the Carpatho-Pannonian and the Ponto-Caspian regions. In the Holocene, C. vindobonensis colonized between the Sudetes and the Carpathians to the north, where its recent and current distribution may have been facilitated by anthropogenic translocations. Together, these data suggest a possible non-steppic origin of C. vindobonensis. Further investigation may reveal the extent to which the steppic snail assemblages consist partly of Holocene newcomers

Expression of DLK1 and MEG3 genes in porcine tissues during postnatal development

The Drosophila-like homolog 1 (DLK1), a transmembrane signal protein similar to other members of the Notch/Delta/Serrate family, regulates the differentiation process in many types of mammalian cells. Callipyge sheep and DLK1 knockout mice are excellent examples of a fundamental role of the gene encoding DLK1 in muscle growth and fat deposition. DLK1 is located within co-regulated imprinted clusters (the DLK1/DIO3 domain), along with other imprinted genes. Some of these, e.g. the RNA coding MEG3 gene, presumedly interfere with DLK1 transcription. The aim of our study was to analyze DLK1 and MEG3 gene expression in porcine tissues (muscle, liver, kidney, heart, brain stem) during postnatal development. The highest expression of both DLK1 and MEG3 variant 1 (MEG3 var.1) was observed in the brain-stem and muscles, whereas that of MEG3 variant 2 (MEG3var.2) was the most abundant in muscles and the heart. During development (between 60 and 210 days of age) expression of analyzed genes was down-regulated in all the tissues. An exception was the brain- stem, where there was no significant change in MEG3 (both variants) mRNA level, and relatively little decline (2-fold) in that of DLK1 transcription. This may indicate a distinct function of the DLK1 gene in the brain-stem, when compared with other tissues

Geographical variation in morphology of Chaetosiphella stipae stipae Hille Ris Lambers, 1947 (Hemiptera: Aphididae: Chaitophorinae)

Chaetosiphella stipae stipae is a xerothermophilous aphid, associated with Palaearctic temperate steppe zones or dry mountain valleys, where there are grasses from the genus Stipa. Its geographical distribution shows several populations that are spread from Spain, across Europe and Asia Minor, to Mongolia and China. Geographical variation in chaetotaxy and other morphological features were the basis to consider whether individuals from different populations are still the same species. Moreover, using Ch. stipae stipae and Stipa species occurrences, as well as climatic variables, we predict potential geographical distributions of the aphid and its steppe habitat. Additionally, for Stipa species we projected current climatic conditions under four climate change scenarios for 2050 and 2070. While highly variable, our results of morphometric analysis demonstrates that all Ch. stipae stipae populations are one very variable subspecies. And in view of predicted climate change, we expect reduction of Stipa grasslands. The disappearance of these ecosystems could result in stronger separation of the East-European and Asian steppes as well as European ‘warm-stage’ refuges. Therefore, the geographic morphological variability that we see today in the aphid subspecies Ch. stipae stipae may in the future lead to speciation and creation of separate subspecies or species

Odkształcenia w procesie spęczania swobodnego

In the paper strain distribution in materials commonly referred to as soft materials (electrolytic copper 99,9 % Cu, annealed) and hard ones (steel 20, containing 0,2 % C) produced during hot upsetting process. Numerical calculations were performed with a use of commercial software QForm2D/3D. Significance of the influence of friction forces in the head surface on the free surface profile and distor-tion of rectangular coordination grid of deformations, as well as, effective strain distribution, in various stages of the process was investigated. The results indicate changes in nonuniformity of strain in obtained forgings.W pracy analizowano rozkład odkształceń w materiałach potocznie zwanych miękkimi (miedź elektrolityczna Cu99,9E, zawierająca 99,90% Cu, stan miękki) lub twardymi (stal 20, zawierająca 0,2% C), powstającymi przy ich spęczaniu swobodnym na gorąco. Obliczenia numeryczne wykonano programem QFORM2D/3D. Wykazano istotny wpływ sił tarcia powierzchniowego na zmiany kształtu po-bocznicy i zniekształcenie linii siatki koordynacyjnej oraz rozkład intensywności odkształcenia na przekroju poprzecznym odkuwek, zachodzący w różnych fazach realizacji procesu spęczania. Wyniki te świadczą o przebiegu nierównomierności odkształcenia w spęczanych odkuwkach

Odporność korozyjna oraz mikrostruktura stali AISI 316L po odkształceniu plastycznym na zimno

In the paper, results of microstructure and hardness examination of cold-worked alloyed steel AISI 316L are presented. In addition, determined was corrosion resistance of the steel in the Ringer solution. Corrosion tests were performed after cold working with 10, 20, 30, 40 and 50% ratio. Potentiodynamic tests included recording polarisation curves as well as determining corrosive potential and corrosive current for various cold working ratios. Cross-sections of the specimens after corrosion tests were observed and analysed using a scanning microscope.W artykule przedstawiono wyniki badań mikrostruktury oraz twardości stali stopowej AISI 316L odkształconej plastycznie. Przeprowadzono również badania odporności korozyjnej tej stali wyznaczone w roztworze Ringera. Badania przeprowadzono w celu określenia zmian odporności korozyjnej stali, poddanej kształtowaniu plastycznemu na zimno, po uzyskaniu zgniotów 10, 20, 30, 40 oraz 50%. Zakres badań potencjodynamicznych obejmował: rejestrację krzywych polaryzacyjnych, określenie wartości potencjału korozyjnego i prądu korozyjnego przy różnych stopniach zgniotu. Po przeprowadzonych badaniach korozyjnych dokonano obserwacji powierzchni próbek za pomocą mikroskopu skaningowego w celu zarejestrowania powstałych zmian