Search results for " zoology"
showing 10 items of 2242 documents
Peritoneal cavity phagocytes from the teleost sea bass express a glucocorticoid receptor (cloned and sequenced) involved in genomic modulation of the…
2005
Abstract To gain further insight into the role of cortisol in Wsh innate immune responses, we cloned and sequenced a 2592 bp cDNA from sea bass (Dicentrarchus labrax) peritoneal leukocytes (PCLs) encoding a glucocorticoid receptor (DlGR1). The deduced aminoacid sequence displayed that DlGR1 belong to a multigenic family of steroid hormone receptors, and exhibited high homology (80%) to the Burton’s mouth breeder (Haplochromis burtoni) HbGR1. The DlGR1 functional domains presented homologies with those of several vertebrate species. In situ hybridization assay revealed that DlGR1 was expressed in macrophages and neutrophils from the peritoneal cavity. Since in a previous paper, sea bass PCL …
The banding pattern of polytene chromosomes of Drosophila guanche compared with that of D. subobscura.
1987
A detailed map of the salivary gland chromosomes of Drosophila guanche is presented and compared to the standard gene arrangements of D. subobscura. Generally, the polytene chromosomc banding patterns of the two species show a high degrce of homology. Only Segment I of the sex chromosome (Chromosome A) shows marked differences. The banding pattern proposed for this segment in D. guanche could have originated from a cluster of overlapping inversions including A1 arrangement.
Control of ovarian steroidogenesis in insects: A locust neurohormone is active in vitro on blowfly ovaries
2009
0016-6480 doi: DOI: 10.1016/j.ygcen.2009.04.034; Ovarian steroidogenesis controlling insect reproduction is mainly regulated by brain gonadotropins liberated from corpora cardiaca (CC). Till now, different neurohormones have been identified in two insect groups only, locusts and mosquitoes, and it is unknown whether they could be active in other insects. In order to complete previous observations on the control of ovarian steroidogenesis in the blowfly, Phormia regina, we examined whether neuropeptides isolated from locust CC have an effect in vitro on ovarian steroidogenesis in our dipteran model. Our experiments showed that crude extracts from locust CC efficiently stimulated steroidogene…
Alternative sites for ecdysteroid production in insects
1990
Summary Several evidences have been obtained in various insect species demonstrating that, besides prothoracic glands and ovaries, other tissues could be alternative sites of moulting hormone production. After a detailed review on the various methods of investigation and criteria required to validate such observations, the nature of these sites, namely oenocytes, epidermis and testes, is discussed. Their possible involvement in moulting and/or reproduction is analyzed, giving the opportunity to put forward several new hypotheses. In particular, autocrine and paracrine secretions of ecdysteroids could play a role in localized developmental events, more difficult to control from endocrine gla…
529. PROPROTEIN CONVERTASE 6 PLAYS A CRITICAL ROLE IN MODULATING THE HUMAN ENDOMETRIAL EPITHELIUM FOR RECEPTIVITY AND IMPLANTATION
2009
Successful embryo implantation is an important step in establishing pregnancy, requiring a healthy embryo and a receptive endometrium. Establishment of endometrial receptivity involves morphological and physiological changes initially in the endometrial epithelium, but the underlying molecular mechanisms are not fully understood. We have previously demonstrated that proprotein convertase 5/6 (PC6), a member of the proprotein convertase (PC) family, is up-regulated in the endometrium specifically at implantation in association with epithelial differentiation, in the human and monkey. PCs convert a range of precursor proteins of important functions into their bioactive forms; they are thus r…
Multidirectional chromosome painting reveals a remarkable syntenic homology between the greater galagos and the slow loris.
2006
We report on the first reciprocal chromosome painting of lorisoids and humans. The chromosome painting showed a remarkable syntenic homology between Otolemur and Nycticebus. Eight derived syntenic associations of human segments are common to both Otolemur and Nycticebus, indicative of a considerable period of common evolution between the greater galago and the slow loris. Five additional Robertsonian translocations form the slow loris karyotype, while the remaining chromosomes are syntenically equivalent, although some differ in terms of centromere position and heterochromatin additions. Strikingly, the breakpoints of the human chromosomes found fragmented in these two species are apparentl…
Beneficial Effect of Melatonin on Blastocyst In Vitro Production from Heat-Stressed Bovine Oocytes
2013
Melatonin may play an important role in protecting gametes and embryos from the potential harmful effects of oxidative stress. In this study, we first examined two different heat stress (HS) treatments for in vitro oocyte maturation (Experiment 1: 38.5 vs 41.0°C, during the first 20 h; Experiment 2: 38.5 vs 41.5°C, during the entire period) on bovine oocyte maturation and embryo development. Second, we tested different melatonin concentrations added to the maturation and culture medium (Experiment 3: 0, 10(-12) , 10(-9) , 10(-4) m; Experiment 4: 0, 10(-3) m), both with and without HS (38.5 or 41.5°C, respectively). In Experiment 1, the HS treatment resulted in a lower maturation rate and …
Effect of propylene glycol on pre- and post-partum performance by dairy ewes
2005
This study was carried out in order to determine the effects, after feeding propylene glycol to Valle del Belice ewes 30 days prepartum and 30 days postpartum, on metabolic profiles, body-condition score, milk yield, milk composition, milk clotting ability and the performance of suckling lambs. Ewes were blocked by parity, body-condition score and previous milk production, and assigned randomly to either a control diet or a diet containing propylene glycol fed at the rate of 80 g/ewe/day (low PG) or 160 g/ewe/day (high PG). Feeding propylene glycol prepartum decreased the concentration of BHBA and NEFA and increased the concentration of glucose in the ewes’ plasma. Milk yield from ewes fed …
Pheromones linked to sexual behaviors excite the appetitive phase of feeding behavior of Aplysia fasciata . I. Modulation and excitation of appetitiv…
1998
Pheromones presumably secreted by mating conspecifics – as well as homogenates containing tissue that is homologous with the atrial gland – increase the time that Aplysia fasciata spend feeding. This effect is caused by increasing the number of feeding episodes initiated in response to food, whereas the duration of a feeding bout remains unchanged. The increase in the number of feeding episodes is related to increases in head waving and crawling, i.e., appetitive movements that bring the animal into contact with food, as well as an increase in the responsiveness to food after it is contacted. Releasing a homogenate containing atrial gland tissue, or egg laying hormone, in the water near the…
Electrical responses of homing pigeon and guinea pig Purkinje cells to pineal indoleamines applied by microelectrophoresis
1984
The effects of microelectrophoretically applied melatonin (aMT), 5-methoxytryptophol (ML), 5-hydroxytryptophol (HL) and noradrenaline (NA) on the electrical activity of cerebellar Purkinje and other cells during both day- and nighttime were studied in urethane-anesthetized intact and pinealectomized homing pigeons and guinea pigs.