scholarly journals Gonadal development and gametogenesis in the threatened freshwater siluroid fish, Horabagrus brachysoma (Gunther, 1864): A morpho-histological perspective

2018 ◽  
Vol 65 (4) ◽  
Author(s):  
Lekshmi R Chandran ◽  
G. Prasad
Keyword(s):  
Primordial Germ Cells ◽  
Gonadal Development ◽  
Female Reproduction ◽  
Spawning Period ◽  
Macroscopic Appearance ◽  
Distinctive Features ◽  
Zona Radiata ◽  
Maturity Stages ◽  
Five Phases ◽  
First Time

The macro-morphology and histology of the reproductive system together with cytology of the process of gametogenesis in Asian sun catfish, Horabagrus brachysoma (Gunther, 1864) were investigated. A maturity key for horabagrids, based on macroscopic appearance of gonads at different stages of maturity was established for the first time. The distinctive features of male genital system were the digitiform testes, absence of seminal vesicles and five morphological maturity stages. Unrestricted semicystic spermatogenic activity with seven cytological stages was recognised viz., primordial germ cells, primary spermatogonia, secondary spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids and spermatozoa. The classic cystovarian, group synchronic ovary, with five morphological maturity stages and a single spawning period were the peculiarities of female reproduction. The process of oogenesis progressed through five phases viz., previtellogenic, cytoplasmic growth, vitellogenic, yolky and mature. The sequence of oocyte maturation was: oogonia, chromatin nuclear, peri-nuclear, cortical alveolar, yolky and mature. Vitellogenesis was initiated in oocytes of maturing or stage-Il ovary. No liqueification of yolk was observed. Atresia was observed in vitellogenic and mature oocytes only. Corpus luteum like structure was present in ovaries with vitellogenic and yolky oocytes. A very prominent zona radiata of thickness 16.5 μm covered mature oocytes.

Implication of the distinctive bipolar intracardiac electrograms for ventricular arrhythmias arising from different regions of ventricular outflow tract

EP Europace ◽  
2020 ◽  
Vol 22 (9) ◽  
pp. 1367-1375
Author(s):  
Jia Li ◽  
Weiqian Lin ◽  
Cheng Zheng ◽  
Chi Zhang ◽  
Jiji Yu ◽  
...  
Keyword(s):  
Ventricular Arrhythmias ◽  
Ventricular Outflow Tract ◽  
High Amplitude ◽  
Outflow Tract ◽  
Correct Identification ◽  
Aortic Sinus ◽  
Distinctive Features ◽  
Long Duration ◽  
Target Sites ◽  
First Time

Abstract Aims To investigate the characteristics of bipolar intracardiac electrograms (bi-EGMs) in target sites of ventricular arrhythmias (VAs) originating from different regions of ventricular outflow tract (VOT). Methods and results Two hundred and seventy patients undergoing first-time ablation for VAs originated from distal great cardiac vein (DGCV), aortic sinus cusps (ASCs), or pulmonary sinus cusps (PSCs) were enrolled in present study. Local intracardiac bipolar recordings on 243 successful sites and 506 attempted but unsuccessful ablation sites were analysed. Specific potentials in bi-EGMs on successful sites were more common compared with unsuccessful sites (76.95%, 187/243 vs. 25.49%, 129/506, P < 0.05). A total of 60.00% (81/135) patients in ASCs group presented a presystolic short-duration fractionated potential, higher than 23.21% (13/56) in DGCV and 23.08% (12/52) in PSCs (all P < 0.05); 44.23% (23/52) patients in PSC group showed a presystolic high-amplitude discrete potential, while 1.79% (1/56) in DGCV and 2.22% (3/135) in ASCs (all P < 0.05); 41.07% (23/56) patients in DGCV group showed bi-EGMs of presystolic long-duration multicomponent fractionated potential, which was significantly higher than 3.85% (2/52) in PSCs and 4.44%(6/135) in ASCs (all P < 0.05). Conclusion Distinctive morphology of bi-EGMs during VAs can be found in different regions of VOT, which probably due to changes in the arrangements of myocardial sleeves. Correct identification and better understanding of the distinctive features of these bi-EGMs with regards to the anatomic location was important, the presence of specific potentials may add help in successful ablation.

Transcription factor GATA-4 is expressed in a sexually dimorphic pattern during mouse gonadal development and is a potent activator of the Mullerian inhibiting substance promoter

Development ◽  
1998 ◽  
Vol 125 (14) ◽  
pp. 2665-2675 ◽  
Author(s):  
R.S. Viger ◽  
C. Mertineit ◽  
J.M. Trasler ◽  
M. Nemer
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Sexual Dimorphism ◽  
Sex Differentiation ◽  
Primordial Germ Cells ◽  
Gonadal Development ◽  
Downstream Target ◽  
Müllerian Inhibiting Substance ◽  
Coordinated Expression ◽  
Mullerian Inhibiting Substance

Mammalian gonadal development and sexual differentiation are complex processes that require the coordinated expression of a specific set of genes in a strict spatiotemporal manner. Although some of these genes have been identified, the molecular pathways, including transcription factors, that are critical for the early events of lineage commitment and sexual dimorphism, remain poorly understood. GATA-4, a member of the GATA family of transcription factors, is present in the gonads and may be a regulator of gonadal gene expression. We have analyzed the ontogeny of gonadal GATA-4 expression by immunohistochemistry. GATA-4 protein was detected as early as embryonic day 11.5 in the primitive gonads of both XX and XY mouse embryos. In both sexes, GATA-4 specifically marked the developing somatic cell lineages (Sertoli in testis and granulosa in ovary) but not primordial germ cells. Interestingly, abundant GATA-4 expression was maintained in Sertoli cells throughout embryonic development but was markedly down-regulated shortly after the histological differentiation of the ovary on embryonic day 13.5. This pattern of expression suggested that GATA-4 might be involved in early gonadal development and possibly sexual dimorphism. Consistent with this hypothesis, we found that the Mullerian inhibiting substance promoter which harbors a conserved GATA element is a downstream target for GATA-4. Thus, transcription factor GATA-4 may be a new factor in the cascade of regulators that control gonadal development and sex differentiation in mammals.

scholarly journals Morphology and Timing of Spawning of Umatilla Dace (Rhinichthys umatilla) in the Slocan River, British Columbia

2016 ◽  
Vol 130 (3) ◽  
pp. 224
Author(s):  
Louise Porto ◽  
Crystal Lawrence
Keyword(s):  
British Columbia ◽  
Aquatic Macrophytes ◽  
Columbia River Basin ◽  
Terrestrial Vegetation ◽  
Spawning Period ◽  
Habitat Features ◽  
In The Wild ◽  
Males And Females ◽  
First Time ◽  
Timing Of Spawning

Umatilla Dace (Rhinichthys umatilla, Cyprinidae) are endemic to the Columbia River Basin. In Canada, this species is assessed as “threatened”. Little is known about its life history, especially with respect to spawning in the wild. A total of 688 specimens were captured, including 39 mature males and females displaying spawning colouration and tubercles, during minnow trapping and electrofishing surveys conducted on the Slocan River in southern British Columbia, Canada. Fertilized eggs were not observed, but eggs and milt were expressed from ripe individuals. Spawning was estimated to occur from mid-July to mid-September. Aquatic macrophytes and flooded terrestrial vegetation were important habitat features for mature Umatilla Dace leading up to the spawning period on the Slocan River. To our knowledge this is the first time that Umatilla Dace have been captured in spawning condition and observed with spawning colouration and tubercles in the wild in Canada. Results of this study will aid the development of recovery plans and management for this species in British Columbia.

scholarly journals Homozygous Inactivating Mutation inNANOS3in Two Sisters with Primary Ovarian Insufficiency

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Mariza G. Santos ◽  
Aline Z. Machado ◽  
Conceição N. Martins ◽  
Sorahia Domenice ◽  
Elaine M. F. Costa ◽  
...  
Keyword(s):  
Rna Binding ◽  
Mutational Analysis ◽  
Primordial Germ Cells ◽  
Embryonic Cell ◽  
Primary Ovarian Insufficiency ◽  
Primary Amenorrhea ◽  
Female Reproduction ◽  
Ovarian Insufficiency ◽  
Rna Interaction

Despite the increasing understanding of female reproduction, the molecular diagnosis of primary ovarian insufficiency (POI) is seldom obtained. The RNA-binding protein NANOS3 poses as an interesting candidate gene for POI since members of the Nanos family have an evolutionarily conserved function in germ cell development and maintenance by repressing apoptosis. We performed mutational analysis ofNANOS3in a cohort of 85 Brazilian women with familial or isolated POI, presenting with primary or secondary amenorrhea, and in ethnically-matched control women. A homozygous p.Glu120Lys mutation inNANOS3was identified in two sisters with primary amenorrhea. The substituted amino acid is located within the second C2HC motif in the conserved zinc finger domain of NANOS3 andin silicomolecular modelling suggests destabilization of protein-RNA interaction.In vitroanalyses of apoptosis through flow cytometry and confocal microscopy show that NANOS3 capacity to prevent apoptosis was impaired by this mutation. The identification of an inactivating missense mutation inNANOS3suggests a mechanism for POI involving increased primordial germ cells (PGCs) apoptosis during embryonic cell migration and highlights the importance of NANOS proteins in human ovarian biology.

scholarly journals Zona pellucida protein ZP2 is expressed in the oocyte of Japanese quail (Coturnix japonica)

Reproduction ◽  
2010 ◽  
Vol 139 (2) ◽  
pp. 359-371 ◽  
Author(s):  
Mihoko Kinoshita ◽  
Daniela Rodler ◽  
Kenichi Sugiura ◽  
Kayoko Matsushima ◽  
Norio Kansaku ◽  
...  
Keyword(s):  
Western Blot ◽  
Zona Pellucida ◽  
Rnase Protection Assay ◽  
Follicular Development ◽  
Amorphous Structure ◽  
Rnase Protection ◽  
Zona Radiata ◽  
Oocyte Cytoplasm ◽  
First Time

The avian perivitelline layer (PL), a vestment homologous to the zona pellucida (ZP) of mammalian oocytes, is composed of at least three glycoproteins. Our previous studies have demonstrated that the matrix's components, ZP3 and ZPD, are synthesized in ovarian granulosa cells. Another component, ZP1, is synthesized in the liver and is transported to the ovary by blood circulation. In this study, we report the isolation of cDNA encoding quail ZP2 and its expression in the female bird. By RNase protection assay and in situ hybridization, we demonstrate that ZP2 transcripts are restricted to the oocytes of small white follicles (SWF). The expression level of ZP2 decreased dramatically during follicular development, and the highest expression was observed in the SWF. Western blot and immunohistochemical analyses using the specific antibody against ZP2 indicate that the 80 kDa protein is the authentic ZP2, and the immunoreactive ZP2 protein is also present in the oocytes. Moreover, ultrastructural analysis demonstrated that the immunoreactive ZP2 localizes to the zona radiata, the perivitelline space, and the oocyte cytoplasm in the SWF. By means of western blot analysis and immunofluorescence microscopy, we detected a possible interaction of the recombinant ZP2 with ZP3 and that this interaction might lead to the formation of amorphous structure on the cell surface. These results demonstrate for the first time that the avian ZP gene is expressed in the oocyte, and that the ZP2 protein in the oocyte might play a role for the PL formation in the immature follicles of the ovary.

70 GONADAL DEVELOPMENT IN GUINEA PIG MALES (CAVIA PORCELLUS)

2016 ◽  
Vol 28 (2) ◽  
pp. 164
Author(s):  
F. Oliveira ◽  
A. Santos ◽  
A. A. Neto
Keyword(s):  
Guinea Pig ◽  
Sertoli Cells ◽  
Sexual Differentiation ◽  
Primordial Germ Cells ◽  
Gonadal Development ◽  
Postnatal Period ◽  
Seminiferous Tubules ◽  
Morphological Description ◽  
Hormonal Function ◽  
Gonad Differentiation

Sexual differentiation in mammals is an event that presents many variations between species. Because it is related to hormonal function, any imbalance in the androgens and estrogens production can lead to malformations. Because sexual differentiation occurs in different ways among various animals, the recognition of their peculiarities becomes important in order to correct reproductive handling in different species. Considering that the guinea pig is commonly used as an experimental model in the reproductive area, the goal of this work was to perform a morphological description of gonad differentiation of the male guinea pig during embryonic development. In total, 11 conceptuses with ages 25 (n = 3), 30 (n = 2), 40 (n = 2), 50 (n = 2), and 65 (n = 2) days were used for light microscopy processing. The embryos at 25 days were processed completely. For the others, the gonads were dissected. The samples were dehydrated in alcohol, embedded in paraffin, and 5-µm sections were stained with hematoxylin-eosin. In the guinea pig gonad at 25 days gestation, there was a presence of gonadal cords, formed by condensation of somatic cells, which is characteristic of an undifferentiated gonad. In addition, we observed the presence of mesonephric and paramesonephric ducts in different embryos, indicating that other genital system organs were not formed. For the 30 days of development of guinea pigs, we observed that gonadal cords were differentiated in testicular cords by invasion of mesenchymal and endothelial cells, and also composed of Sertoli cells and primordial germ cells. These cords were among a large amount of testicular mesenchyme at the 40-day group. With 50- and 65-day development samples, the gonad was completely differentiated into testicle, with the presence of spermatogonia and Sertoli cells in the seminiferous tubules, and a large amount of interstitial Leydig cells around the tubules. We conclude that gonadal differentiation in guinea pig males occurs around the middle of pregnancy, between 25 and 30 days and that, before the end of the pregnancy, at 50 days, the testicle presents morphology similar to that found in the postnatal period.

scholarly journals THE POWER OF THE SMALL: THE EXAMPLE OF Paracoccidioides brasiliensis CONIDIA

2015 ◽  
Vol 57 (suppl 19) ◽  
pp. 5-10 ◽  
Author(s):  
Angela RESTREPO ◽  
Luz Elena CANO ◽  
Ángel GONZALEZ
Keyword(s):  
Yeast Cell ◽  
Paracoccidioides Brasiliensis ◽  
Eukaryotic Cell ◽  
Male Mice ◽  
Distinctive Features ◽  
Pulmonary Lesions ◽  
Large Numbers ◽  
First Time ◽  
Shape And Size

SUMMARYResearch on Paracoccidioides brasiliensis has centered in the yeast cell probably because of the lack of distinctive features in the mycelium. In 1942 and for the first time, lateral conidia were noticed in the fungus' hyphae. Later on, Brazilian, Venezuelan and Argentinean researchers described "aleurias" when the fungus was grown in natural substrates. In 1970 authors became interested in the conidia and were able to obtain them in large numbers and treat them as individual units. Their shape and size were defined and the presence of all the elements of a competent eukaryotic cell were demonstrated. Conidia exhibited thermal dimorphism and, additionally, when given intranasally to BALB/c male mice, they converted into yeasts in the lungs and produce progressive pulmonary lesions with further dissemination to other organs. Studies on the phagocyte-conidia interaction were revealing and showed that these versatile structures allow a better understanding of the host- P. brasiliensisinteractions.

Comparative analysis of the efficiency of oil–producing companies in Russia and the world

2020 ◽  
Author(s):  
Arina E. Link ◽  
◽  
Mikhail V. Mishenin ◽  
Keyword(s):  
Comparative Analysis ◽  
Oil And Gas ◽  
Distinctive Features ◽  
Foreign Companies ◽  
The World ◽  
Tax Deductions ◽  
Cost Of Production ◽  
Oil And Gas Companies ◽  
First Time ◽  
Oil And Gas Sector

The study compares domestic and foreign companies in the oil and gas sector for the first time and identifies the distinctive features of each group. The results of calculations showed that the profit of any large oil and gas company is affected by revenue, cost of production and the amount of tax deductions. Moreover, the refinancing rate of the country where the company is registered is important for the activities of oil and gas companies.

Gonadal Maturation and Histological observations of S. curvifrons in River Jhelum Kashmir

2018 ◽  
Author(s):  
Sauliheen Qadri ◽  
Tasaduq H Shah ◽  
M. H. Balkhi ◽  
Bilal A. Bhat ◽  
F. A. Bhat ◽  
...  
Keyword(s):  
Gonadosomatic Index ◽  
Gonadal Development ◽  
Spawning Season ◽  
Gonadal Maturation ◽  
Maturity Stages ◽  
Preparatory Phase

The objective of the present study is to describe the phases of gonadal development and determine the spawning season of Schizothorax curvifrons in River Jhelum Kashmir. A total of 298 fish specimen were studied to analyse the gonadosomatic index and maturity stages of S. curvifrons. Five maturity stages namely Immature phase, Preparatory phase, Maturing phase, Ripe/spawning phase and Spent phase were observed in the gonads. Based on GSI values and gonadal conditions, April to June appears to be the spawning season for S. curvifrons

scholarly journals Comparative Analysis of Pharmacologic and/or Genetic Disruption of Cyclooxygenase-1 and Cyclooxygenase-2 Function in Female Reproduction in Mice*

Endocrinology ◽  
2001 ◽  
Vol 142 (7) ◽  
pp. 3198-3206 ◽  
Author(s):  
Jeff Reese ◽  
Xuemei Zhao ◽  
Wen-Ge Ma ◽  
Naoko Brown ◽  
Timothy J. Maziasz ◽  
...  
Keyword(s):  
Early Pregnancy ◽  
Synergistic Effects ◽  
Female Reproduction ◽  
Cox Inhibitors ◽  
Cyclooxygenase 1 ◽  
Simultaneous Inhibition ◽  
Cox 2 ◽  
Alternative Sources ◽  
First Time ◽  
Cox 1

Abstract Cyclooxygenase (COX)-derived prostaglandins are critical in female reproduction. Gene targeting studies show that ovulation, fertilization, implantation, and decidualization are defective in COX-2 deficient mice. We used genetic and pharmacologic approaches to perturb COX function and examine the differential and synergistic effects of inhibition of COX-1, COX-2, or of both isoforms on reproductive outcomes during early pregnancy in mice. The results demonstrate that simultaneous inhibition of COX-1 and COX-2 produces more severe effects on early pregnancy events than inhibition of either isoform alone. The effects of pharmacological inhibition of COX-2 on female reproductive functions were less severe than the null mutation of the COX-2 gene. A combined approach showed that COX-2 inhibition in COX-1−/− mice induced complete reproductive failure, suggesting a lack of alternative sources of prostaglandin synthesis. This investigation raises caution regarding the indiscriminate use of COX inhibitors and shows for the first time the distinct and overlapping pathways of the cyclooxygenase systems in female reproduction.

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