Biological invasions are increasingly recognized as a potent force altering native ecosystems worldwide. Many of the best documented cases involve the massive invasions of North America by plant and animal taxa native to Europe. In this study, we use DNA barcoding to survey the occurrence and genetic structure of two major groups of soil invertebrates in both their native and introduced ranges:Collembola and earthworms. Populations of ten species of earthworms and five species of Collembola were barcoded from both continents. Most of these species exhibited a similar genetic structure of large and stable populations in North America and Europe, a result supporting a scenario of multiple invasions. This was expected for earthworm species involved in human economic activities, but not foreseen for Collembola species de facto unintentionally introduced. This study also establishes that invasive species surveys employing DNA barcoding gain additional resolution over those based on morphology as they Electronic supplementary material The online version of this article (
Collembola is one of the major functional groups in soil as well as a model taxon in numerous disciplines. Therefore the accurate identification of specimens is critical, but could be jeopardised by cases of cryptic diversity. Several populations of six well characterised species of springtails were sequenced using the COI barcode fragment as a contribution to the global Collembola barcoding campaign. Each species showed high intraspecific divergence, comparable to interspecific sequence divergence values observed in previous studies and in 10 congeneric species barcoded here as a reference. The nuclear marker, 28S, confirmed all the intraspecific lineages found with COI, supporting the potential specific status of these entities. The implications of this finding for taxonomy and for disciplines relying on species names, such as evolution and ecology, are discussed.
Phytoestrogens, polyphenolic compounds derived from plants, are more and more common constituents of human and animal diets. In most of the cases, these chemicals are much less potent than endogenous estrogens but exert their biological effects via similar mechanisms of action. The most common source of phytoestrogen exposure to humans as well as ruminants is soybean-derived foods that are rich in the isoflavones genistein and daidzein being metabolized in the digestive tract to even more potent metabolites—para-ethyl-phenol and equol. Phytoestrogens have recently come into considerable interest due to the increasing information on their adverse effects in human and animal reproduction, increasing the number of people substituting animal proteins with plant-derived proteins. Finally, the soybean becomes the main source of protein in animal fodder because of an absolute prohibition of bone meal use for animal feeding in 1995 in Europe. The review describes how exposure of soybean-derived phytoestrogens can have adverse effects on reproductive performance in female adults.
Although their functional importance in ecosystems is increasingly recognized, soil-dwelling micro-arthropods are usually poorly known in comparison with their above-ground counterparts. Collembola constitute a significant and species-rich component of the soil biodiversity, but it remains a woefully understudied group because of the taxonomic impediment. The ever-increasing use of molecular taxonomic tools, such as DNA barcoding, provides a possible solution. Here, we test the use of this approach through a diversity survey of Collembola from the vicinity of Churchill, Manitoba, Canada, and compare the results with previous surveys in the same area and in other sub-Arctic regions. The systematic barcoding campaign at Churchill revealed a diverse collembolan fauna consisting of 97 species-level MOTUs in six types of habitats. If all these MOTUs are confirmed as species, this richness would be far higher than prior records for Arctic Canada and could lead to reconsider the actual diversity of the group in Arctic environments.
Abstract. The main function of the corpus luteum (CL) is production of progesterone (P4). Adequate luteal function to secrete P4 is crucial for determining the physiological duration of the estrous cycle and for achieving a successful pregnancy. The bovine CL grows very fast and regresses within two days at luteolysis. The mechanism controlling the development and secretory function of the bovine CL may involve many factors that are produced both within and outside the CL. Some of these regulators seem to be prostaglandins (PGs), oxytocin (OT) and adrenergic factors such as noradrenaline (NA). Recently, there has been some evidence that P4 acts within the bovine CL as an autocrine and/or paracrine regulator. Each of these factors may act on the CL independently or may modify the actions of others. The purpose of this paper is to review and discuss the possible roles of OT, PGs, P4 and NA as luteotropic auto/paracrine regulators in the bovine CL. Furthermore, intraluteal mechanisms controlling the sensitivity of the CL to extragonadal PGF2α are discussed.
Information on the prevalence of subclinical endometritis and its mechanism in repeat breeding cows is very limited. The aims of this study were: a) to evaluate the incidence of this disorder with cytobrush cytology b) to analyze mRNA expression of tumor necrosis factor α (TNFα) and inducible nitric oxide synthase (iNOS) in endometrial biopsy samples collected from repeat breeding cows with and without subclinical endometritis.Two experiments were carried out. In experiment 1, 112 (12.4%) repeat breeding cows (inseminated at least 3 times and not pregnant) were selected out of 902 cows from 8 dairy herds. Cytobrush cytology was performed on these cows, using the threshold of 10% PMNs in uterine smears. The results showed that 45 out of the 112 cows (40.2%) were diagnosed as having subclinical endometritis. In experiment 2, uterine biopsy samples were taken from repeat breeding cows with subclinical endometritis (n = 10) and without this disorder (n = 10). Using reverse transcription-PCR, the mRNA expression of TNFα and iNOS was determined. A statistically significant increase in expression of both substances was measured in the group of cows with subclinical endometritis (p < 0.05).These results provide evidence for a high prevalence of subclinical endometritis in repeat breeding cows as well as the involvement of TNFα and iNOS pathways in the regulation of this pathological condition.
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