Search results for "mammalia"

Progenitor death drives retinal dysplasia and neuronal degeneration in a mouse model of Atrip-Seckel syndrome

2020

ABSTRACT Seckel syndrome is a type of microcephalic primordial dwarfism (MPD) that is characterized by growth retardation and neurodevelopmental defects, including reports of retinopathy. Mutations in key mediators of the replication stress response, the mutually dependent partners ATR and ATRIP, are among the known causes of Seckel syndrome. However, it remains unclear how their deficiency disrupts the development and function of the central nervous system (CNS). Here, we investigated the cellular and molecular consequences of ATRIP deficiency in different cell populations of the developing murine neural retina. We discovered that conditional inactivation of Atrip in photoreceptor neurons …

Evolutionary conflicts in a small mammal : behavioural, physiological and genetic differences between the sexes

2011

Triacylglycerol Analysis in Human Milk and Other Mammalian Species: Small-Scale Sample Preparation, Characterization, and Statistical Classification …

2015

In this work, a method for the separation of triacylglycerols (TAGs) present in human milk and from other mammalian species by reversed-phase high-performance liquid chromatography using a core–shell particle packed column with UV and evaporative light-scattering detectors is described. Under optimal conditions, a mobile phase containing acetonitrile/n-pentanol at 10 °C gave an excellent resolution among more than 50 TAG peaks. A small-scale method for fat extraction in these milks (particularly of interest for human milk samples) using minimal amounts of sample and reagents was also developed. The proposed extraction protocol and the traditional method were compared, giving similar results…

Data from: Negative frequency-dependent selection of sexually antagonistic alleles in Myodes glareolus

2011

Sexually antagonistic genetic variation, where optimal values of traits are sex-dependent, is known to slow the loss of genetic variance associated with directional selection on fitness-related traits. However, sexual antagonism alone is not sufficient to maintain variation indefinitely. Selection of rare forms within the sexes can help to conserve genotypic diversity. We combined theoretical models and a field experiment with Myodes glareolus to show that negative frequency-dependent selection on male dominance maintains variation in sexually antagonistic alleles. In our experiment, high-dominance male bank voles were found to have low-fecundity sisters, and vice versa. These results show …

Embryo effects in human implantation: embryonic regulation of endometrial molecules in human implantation.

2001

: Embryonic implantation requires coordinated development of the blastocyst and the maternal endometrium. Considerable advances have been made in the understanding of the cell biology of human embryo and maternal endometrium as separate entities. Nevertheless, communication between them and their reciprocal effects on each other constitute an exciting and as-yet unsolved problem in reproductive medicine. Cross-talk among the embryo, endometrium, and the corpus luteum are known to occur in ruminants and primates; more specifically, endometrial-embryonic interactions have been reported in rodents and primates. Here, we present updated information in humans on the embryonic regulation of endom…

Do human concepti have the potential to enter into diapause?

1999

Although there is no direct evidence as to whether human concepti have the potential to enter into diapause before implantation, the possibility that human concepti may be capable of following this developmental pathway if exposed to an appropriate environment cannot be ruled out. Direct evidence remains elusive because of the ethical restraints associated with research activities within this area of knowledge. If conceptus diapause has evolved in primates and persists at the present time despite its apparent limited or no adaptive advantage, artificial induction of diapause in humans may have clinical implications for increasing: (i) the viability of concepti after biopsy, freezing-thawing…

Toxicity effects of the organic UV-filter 4-Methylbenzylidene camphor in zebrafish embryos

2019

Abstract Ultraviolet (UV) filters are widely used in personal care products and due to their lipophilicity these chemicals tend to bioaccumulate in the aquatic biota. 4-Methylbenzylidene camphor (4-MBC) is one of the most used UV-filters, and it is commonly detected in freshwater fish tissues. This substance is suspected to be an endocrine disruptor due to its interaction with Hypothalamus-Pituitary-Gonadal (HPG) and HP-Thyroid (HPT)-axis. The main objective of this study was to evaluate the effects of 4-MBC on apical endpoints, biochemical markers and on genes involved in endocrine pathways in Danio rerio. Zebrafish embryos were exposed to 4-MBC (0.083–0.77 mg/l) from 0 to 96 h post-fertil…

Retinoid receptors and vitamin A deficiency: differential patterns of transcription during early avian development and the rapid induction of RARs by…

2003

The functional links of specific retinoid receptors to early developmental events in the avian embryo are not known. Before such studies are undertaken, knowledge is required of the spatiotemporal expression patterns of the receptor genes and their regulation by endogenous retinoic acid levels during the early stages of development. Here, we report the expression patterns of mRNAs for RARalpha, RARalpha2, RARbeta2, RARgamma, RARgamma2, RXRalpha, and RARgamma from neurulation to HH10 in the normal and vitamin A-deficient (VAD) quail embryo. The transcripts for all retinoid receptors are detectable at HH5, except for RXRgamma, which is detected at the beginning of HH6. At the 4/5 somite stage…

Distribution of osteonectin mRNA and protein during human embryonic and fetal development.

1992

We investigated the temporal and spatial distribution of osteonectin during human embryonic and fetal development, using in situ hybridization and immunohistochemistry. Osteonectin gene expression was generally found in cells exhibiting high rates of matrix production/proliferation. In mineralized tissue, a strong signal was obtained in osteoblasts, odontoblasts, and chondrocytes of the upper hypertrophic and proliferative zones. Chondrocytes of the mineralized zone showed no expression throughout the different stages of development. Strong osteonectin expression was found in odontoblasts of developing teeth. In addition, osteonectin mRNA and protein were detected in several non-mineralize…

Development of the coronary arteries in a murine model of transposition of great arteries.

2003

Transposition of great arteries in humans is associated with a wide spectrum of coronary artery patterns. However, no information is available about how this pattern diversity develops. We have studied the development of the coronary arteries in mouse embryos with a targeted mutation of perlecan, a mutation that leads to ventriculo-arterial discordance and complete transposition in about 70% of the embryos. The perlecan-deficient embryos bearing complete transposition showed a coronary artery pattern consisting of right and left coronary arteries arising from the morphologically dorsal and ventral sinuses of Valsalva, respectively. The left coronary artery gives rise to a large septal arter…