Evolutionary history and species delimitations: a case study of the hazel dormouse, Muscardinus avellanarius

Robust identification of species and significant evolutionary units (ESUs) is essential to implement appropriate conservation strategies for endangered species. However, definitions of species or ESUs are numerous and sometimes controversial, which might lead to biased conclusions, with serious consequences for the management of endangered species. The hazel dormouse, an arboreal rodent of conservation concern throughout Europe is an ideal model species to investigate the relevance of species identification for conservation purposes. This species is a member of the Gliridae family, which is protected in Europe and seriously threatened in the northern part of its range. We assessed the extent of genetic subdivision in the hazel dormouse by sequencing one mitochondrial gene (cytb) and two nuclear genes (BFIBR, APOB) and genotyping 10 autosomal microsatellites. These data were analysed using a combination of phylogenetic analyses and species delimitation methods. Multilocus analyses revealed the presence of two genetically distinct lineages (approximately 11 % cytb genetic divergence, no nuclear alleles shared) for the hazel dormouse in Europe, which presumably diverged during the Late Miocene. The phylogenetic patterns suggests that Muscardinus avellanarius populations could be split into two cryptic species respectively distributed in western and central-eastern Europe and Anatolia. However, the comparison of several species definitions and methods estimated the number of species between 1 and 10. Our results revealed the difficulty in choosing and applying an appropriate criterion and markers to identify species and highlight the fact that consensus guidelines are essential for species delimitation in the future. In addition, this study contributes to a better knowledge about the evolutionary history of the species

Morphometrics and genetics highlight the complex history of Eastern Mediterranean spiny mice

© 2020 The Linnean Society of London, Biological Journal of the Linnean Society. Spiny mice of the Acomys cahirinus group display a complex geographical structure in the Eastern Mediterranean area, as shown by previous genetic and chromosomal studies. To better elucidate the evolutionary relationships between insular populations from Crete and Cyprus and continental populations from North Africa and Cilicia in Turkey, genetic and morphometric variations were investigated, based on mitochondrial D-loop sequences, and the size and shape of the first upper molar. The Cypriot and the Cilician populations show idiosyncratic divergence in molar size and shape, while Cretan populations present a geographical structure with at least three differentiated subpopulations, as shown by congruent distributions of haplogroups, Robertsonian fusions and morphometric variation. A complex history of multiple introductions is probably responsible for this structure, and insular isolation coupled with habitat shift should have further promoted a pronounced and rapid morphological evolution in molar size and shape on Crete and Cyprus

Flaxseed and sunflower oil affect egg production and quality in hens exposed to stress

In the study, effects of dietary supplementations with flaxseed oil and sunflower oil on production performance, egg quality, and the eggs' sensory attributes in laying hens exposed to high stocking density stress were investigated. A total of one hundred and forty-four 38-week-old "Atak-S" breed laying hens were used. The hens were divided into two main groups as stress group and non-stress group, which both were further divided into three subgroups: basal diet, 2% flaxseed oil diet, and 2% sunflower oil diet groups. High stocking density stress was induced with a space allowance of 357 cm(2) per hen. All hens were weighed initially and just before the study has been completed, and the body weight gain was calculated. Egg production per hen was daily recorded, and production performance, mean egg weight, and egg mass were estimated. Moreover, eggshell weight, thickness, strength, albumen height, and egg yolk color were measured. Trained panelists evaluated egg samples collected from each subgroup regarding sensory attributes such as taste, flavor, color, and texture. Flaxseed oil decreased egg production and egg mass in the non-stress group while increasing the stress group's same parameters. Sunflower oil increased average egg weight in all hens and paled the egg yolk's yellow color in the stressed hens. Moreover, the non-stress group's eggs were more appealing in taste than those of the stress group. Flaxseed-supplemented diet enhanced the sensory attributes in the eggs of both stress and non-stress groups. Furthermore, neither of the oil supplementations generated a strange or repulsive odor in the eggs. In conclusion, dietary flaxseed oil supplementation might be recommended to improve egg production and egg sensory attributes in stress-exposed laying hens. Sunflower oil supplementation might be offered for increasing egg production and some sensory parameters in both stressed and unstressed hens

Noise Stress-Induced Changes in mRNA Levels of Corticotropin-Releasing Hormone Family Molecules and Glucocorticoid Receptors in the Rat Brain

Noise is a widespread stress resource that may lead to detrimental effects on the health. However, the molecular basis of the stress response caused by noise remains elusive. We have studied the effects of acute and chronic noise stress on stress-related molecules in the hypothalamus and hippocampus and also corticosterone responses. Sprague Dawley rats were randomized into control, acute and chronic noise stress groups. While the chronic noise stress group animals were exposed to 100 dB white noise for 4 h/a day during 30 days, the acute noise stress group of animals was exposed to the same level of stress once for 4 h. The expression profiles of corticotropin-releasing hormone (CRH), CRH1, CRH2 receptors and glucocorticoid receptor (GR) mRNAs were analysed by RT-PCR. Chronic noise stress up-regulated CRH mRNA levels in the hypothalamus. Both acute and chronic noise increased CRH-R1 mRNA in the hypothalamus but decreased it in the hippocampus. GR mRNA levels were decreased by chronic noise stress in the hippocampus. The present results suggest that while corticosterone responses have habituated to continuous noise stress, the involvement of CRH family molecules and glucocorticoid receptors in the noise stress responses are different and structure specific

The effects of vitamin E on some blood parameters in broilers

The purpose of this study was to determine the effects of different doses of vitamin E supplemented into the diet on erythrocyte osmotic fragility and some biochemical parameters. Sixty broilers were randomly divided into four groups of 15 each (one control and three experimental groups). Experimental groups (D1, D2, D3) were fed with a diet supplemented with 100, 200 and 300 ppm of vitamin E respectively. The plasma vitamin E level, and other blood parameters, of all the test subjects were measured in the fifth and seventh week of the study. The plasma vitamin E level of D2 and D3 experimental groups in the fifth week, and the plasma vitamin E level of all three experimental groups in the seventh week of the study increased statistically when compared to the control group. Erythrocyte osmotic fragility of all three experimental groups decreased significantly by the fifth and seventh weeks of the study in comparison with the control group, No significant difference in plasma cholesterol, triglyceride, total protein, ALP (alkaline phosphatase), Ca (calcium), P (phosphorus), AST (aspartate aminotransferase) or ALT (alanin aminotransferase) was found between control and experimental groups by the fifth and seventh weeks. Only the ALP level of all groups decreased statistically by the seventh week of the study in comparison to the fifth week

The effects of thyroid disorders on some haematologic parameters in quail

In this study, the effects of experimentally induced hyperthyroidism and hypothyroidism on the erythrocyte, leucocyte and haematocrit values, the amount of haemoglobin and plasma glucose, cholesterol, triglyceride. creatinine and lactate dehydrogenase (LDH) levels were investigated

Discrimination of 2n=60 Spalax leucodon cytotypes (Spalacidae, Rodentia) in Turkey by means of classical and molecular cytogenetic techniques

Comparative studies among seven populations of 2n = 60 S. leucodon employing classic cytogenetics (G-bands, C-bands, AgNOR-staining), fluorochrome staining, and fluorescence in situ hybridization of telomeric and rDNA probes are reported here for the first time. The studied specimens were assigned to two cytotypes: 2n = 60W and 2n = 60R. The basic karyotype of both cytotypes consisted of eight pairs of subtelocentric and 21 pairs of acrocentric autosomes, subtelocentric X and acrocentric Y chromosomes. Both cytotypes had variable numbers of B-chromosomes (1-3) and variable numbers of autosomal arms (NFa = 74-76) caused by amplification (deletion) of heterochromatin short arms in the second pair. The short arms of subtelocentric chromosomes were comprised of heterochromatin in both cytotypes. Nucleolar organizer regions (NORs) and rDNA clusters were detected at telomeric sites of the short arms in pairs Nos. 3, 5, 6, 9, and 13 in cytotype W, and in the short arms of pair No. 6, 8, 12, 13, and 16 in cytotype R. Different locations of rDNA clusters allowed unambiguous discrimination between two S. leucodon cytotypes possessing the same 2n = 60 and similar NFa (74-76) variability. Our findings suggest a high level of chromosomal divergence, which means that it is possible to consider these cytotypes as a well-differentiated, chromosomal lineage within the leucodon group. Copyright (C) 2008 S. Karger AG, Base

The effects of Saccharomyces cerevisiae extract on the weight of some organs, liver, and pancreatic digestive enzyme activity in breeder hens fed diets contaminated with aflatoxins

The effects of the Saccharomyces cerevisiae extract on some organ, liver, and pancreatic digestive enzymes in breeder hens fed on aflatoxin (AF)-contaminated feed were investigated. Forty-eight 58-wk-old Ross 308 breeder hens were used. The hens were fed diets containing 0 or 100 mu g of AF/kg and 0 or 1 g of S. cerevisiae/kg in a 2 x 2 factorial arrangement of treatments. Although serum alkaline phosphatase levels were significantly higher, serum alkaline aminotransferase (P = 0.068) and gamma-glutamyltransferase (P = 0.067) levels tended to increase (P < 0.05) in hens fed the AF-contaminated diet than those of hens fed the uncontaminated diet. Both AF and S. cerevisiae extract increased (P < 0.001) pancreatic amylase activity, but the effect was not additive, resulting in an AF x S. cerevisiae extract interaction (P < 0.001). a-Amylase activity in duodenum was lower (P < 0.001) in hens fed the AF-contaminated diet. Duodenum a-amylase activity was higher (P = 0.024), but jejunum a-amylase activity was lower in S. cerevisiae extract-supplemented hens than that of nonsupplemented hens. There was a significant interaction between AF and S. cerevisiae extract on pancreatic and duodenal lipase activity. Pancreatic lipase activity decreased in hens fed the AF-contaminated diet. However, S. cerevisiae supplementation extract minimized this effect of AF on pancreatic lipase activity. Duodenal lipase activity was decreased in hens fed the AF-contaminated diet without S. cerevisiae extract supplementation. However, there were not any significant differences between hens fed the AF-contaminated diet and hens fed the uncontaminated diet after S. cerevisiae extract supplementation. Pancreatic trypsin activity was higher (P = 0.044) in hens fed the AF-contaminated diet than that of hens fed the uncontaminated diet. There was a significant interaction between AF and S. cerevisiae extract on pancreatic chymotrypsin activity. It was increased in hens fed the AF-contaminated diet without S. cerevisiae extract supplementation. However, S. cerevisiae extract supplementation counteracted this negative effect of AF on pancreatic chymotrypsin activity. The treatments did not result in any change in duodenal chymotrypsin activity, but S. cerevisiae supplementation decreased (P < 0.05) jejunal chymotrypsin activity. In conclusion, our results showed that addition of 1 g/kg of S. cerevisiae extract reduces the toxic effects of AF on pancreatic lipase and chymotrypsin activity. Therefore, it may be useful to supplement feedstuff with S. cerevisiae extract to reduce the effects of AF in laying breeder hens