Reproduction in Australian Pearl Oysters (Lamellibranchia). III. Pinctada albina (Lamarck): Breeding Season and Sexuality

1958 ◽  
Vol 9 (2) ◽  
pp. 191 ◽  
Author(s):  
DJ Tranter
Keyword(s):  
Germ Cell ◽  
Breeding Season ◽  
Marine Invertebrates ◽  
Sex Change ◽  
The Body ◽  
General Tendency ◽  
Food Reserve ◽  
Pearl Oysters ◽  
Male Sex

Plnctada albina breeds continuously throughout the year, but most actively during April and May when sea temperatures begin to fall. Thus the species resembles the majority of tropical marine invertebrates in the former respect but differs from them in the latter. The heaviest spatfalls occur from June to August when sea temperatures are at a minimum. This species is hermaphrodite, with a, general tendency toward protandry. Both male-female and female-male sex changes, and the bisexual condition which sometimes prevails during change-over, have been observed. Sex change in bivalves is discussed, and it is suggested that the phenomenon can best be explained in terms of a weak hereditary sex-determining mechanism, and germ cell rudiments responsive to the food reserve level in the body such that male differentiation is favoured at lower levels and female differentiation at higher levels.

scholarly journals A PHYSIOLOGICAL STUDY OF SHUKRA DHATU W.S.R. SEXUAL HORMONES

2021 ◽  
Vol 9 (9) ◽  
pp. 2165-2173
Author(s):  
Prakash Choudhary ◽  
Rajesh Kumar Sharma ◽  
Dinesh Chandra Sharma ◽  
Mukesh Saini
Keyword(s):  
Germ Cell ◽  
Human Body ◽  
Primordial Germ Cell ◽  
Good Health ◽  
The Body ◽  
Entire Body ◽  
Sexual Hormones ◽  
Male Sex ◽  
The One ◽  
Definite Role

Ayurveda has described three basic physiological constituents of the human body, viz., Dosha, Dhatu and Mala. In Ayurvedic Science, the one who has balanced Doshas, balanced Agni, properly formed Dhatus, proper elimina- tion of Malas, well-functioning of bodily processes and whose mind, soul, senses are full of bliss is called a healthy person1. So, the formation of Dhatu is also a good indicator of good health there are seven Dhatus ex- plained in Samhitas, those are Rasa, Rakta, Mamsa, Meda, Ashti, Majja and Shukra among all Dhatus, Shukra is considered as the sara of all other Dhatus2. Shukra Dhatu is one of the seven Dhatus in the body and Shukra is white, pure, excellent Dhatu, which is considered as best among all seven Dhatus. According to many Acharyas of Ayurveda, Garbhotpadana (reproduction) is the chief function of Shukra Dhatu, and the important fact is Shukra Dhatu also shows its effect all over the body in the form of Shukradhatusarata because Shukradhatuis located in the entire body. Sperm along with spermatic fluid and male sex hormones are also one part of Shukra Dhatu. Anu Shukra Dhatu (primordial germ cell) is essential for the Shukra Dhatu (Testosterone, Estrogen). Vi- tiation of Shukra dhatu shows Shukra dhatudusti (pathology) in the form of Vriddhi (hyper state) or Kshaya (wan- ing). This vitiation may lead to main infertility and many other physical as well as psychological disorders. All Dhatus have their definite locations in the body; they are present in every cell in subtle form. Every cell possesses the capacity to divide or reproduce itself. Thus, one has to interpret the Garbhotpadana (reproduction) function of Shukra Dhatu. In future, it may be achievable that with the development of the facts; we will discover any content in the cell whichpossesses a definite role in cell division.Sperms along with spermatic fluid and male sex hor- mones are also one Partofshukra, parallel to which females possess Artava. Stri-Shukra excreted during coitus is nothing but the secretions of bartholins, cervical and endometrial glands emergence at theendoforgasm. Keywords:Ayurveda, Stree-Shukra, Shukra Dhatu, Artava, hormones.

scholarly journals The Hypoxic Testicle: Physiology and Pathophysiology

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Juan G. Reyes ◽  
Jorge G. Farias ◽  
Sebastián Henríquez-Olavarrieta ◽  
Eva Madrid ◽  
Mario Parraga ◽  
...  
Keyword(s):  
Germ Cell ◽  
Testicular Torsion ◽  
Oxygen Supply ◽  
Cell Function ◽  
Cell Damage ◽  
The Body ◽  
Body Core Temperature ◽  
Seminiferous Tubules ◽  
Low Oxygen ◽  
Complex Biological Process

Mammalian spermatogenesis is a complex biological process occurring in the seminiferous tubules in the testis. This process represents a delicate balance between cell proliferation, differentiation, and apoptosis. In most mammals, the testicles are kept in the scrotum 2 to 7°C below body core temperature, and the spermatogenic process proceeds with a blood and oxygen supply that is fairly independent of changes in other vascular beds in the body. Despite this apparently well-controlled local environment, pathologies such as varicocele or testicular torsion and environmental exposure to low oxygen (hypoxia) can result in changes in blood flow, nutrients, and oxygen supply along with an increased local temperature that may induce adverse effects on Leydig cell function and spermatogenesis. These conditions may lead to male subfertility or infertility. Our literature analyses and our own results suggest that conditions such as germ cell apoptosis and DNA damage are common features in hypoxia and varicocele and testicular torsion. Furthermore, oxidative damage seems to be present in these conditions during the initiation stages of germ cell damage and apoptosis. Other mechanisms like membrane-bound metalloproteinases and phospholipase A2 activation could also be part of the pathophysiological consequences of testicular hypoxia.

scholarly journals The physical development of the 1th-2nd course students of professional pre-high education institutions

2021 ◽  
pp. 92-95
Author(s):  
Irina Masliak ◽  
Krivoruchko Natalia ◽  
Yuliia Slobodianiuk
Keyword(s):  
High Education ◽  
Cardiovascular System ◽  
Functional State ◽  
Respiratory System ◽  
Physical Development ◽  
The Body ◽  
Average Level ◽  
General Tendency ◽  
Development Indicators ◽  
And Gender

The article provides the results of determining the level of physical development of the 1th-2nd course students of design specialties of the College of Construction, Architecture and Design. The physical development of students was determined by indicators of harmony of the bodybuilding (Kettle index 2), functional state of the cardiovascular system (Ruffier index), and respiratory system (Stange test). Length and weight of the body, heart rate, breathing delay time were measured. As a result of the researches, the “average” level of the physical development is determined in the 1th-2nd course girls and “sufficient” - in boys. Thus, mass-growth indicators of students according to the calculation of Kettle 2 index, both boys and girls correspond to the assessment of 5 points, which indicates a harmonious physique of students; indicators of the functioning of the cardiovascular system (Ruffier Index) of 1st year boys and the 2nd year students make 2 points, which corresponds to the ”below average” level, and the results of the 1st year girls equal to the assessment of 3 points, “average” level; indicators of the functional state of the respiratory system (Stange test) of boys of the 1th-2nd  course correspond to the assessment of 4 points (“above the average” level), and girls of both courses - 3 points (“average” level). In the age and gender aspects, physical development indicators, in general, don’t significantly differ with the general tendency to increase results with age and the dominance of boys over such in girls. The exception is the Ruffier index, where there is an opposite trend - the results decrease with age in girls and they are higher than in boys. Thus, the results of the research indicate the feasibility of introducing the 1th-2nd course students of professional pre-high education of special physical exercises into the process of physical education to improve the functional state of the cardiovascular and respiratory systems.

scholarly journals A universal subcuticular bacterial symbiont of a coral predator, the crown-of-thorns starfish, in the Indo-Pacific

2020 ◽  
Author(s):  
Naohisa Wada ◽  
Hideaki Yuasa ◽  
Rei Kajitani ◽  
Yasuhiro Gotoh ◽  
Yoshitoshi Ogura ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
16S Rrna ◽  
Marine Invertebrates ◽  
Sequence Data ◽  
The Body ◽  
Rrna Gene ◽  
Ecological Knowledge ◽  
Reef Management ◽  
Genetic Traits ◽  
Associated Bacteria

AbstractBackgroundPopulation outbreaks of the crown-of-thorns starfish (Acanthaster planci sensu lato; COTS), a primary predator of reef-building corals in the Indo-Pacific Ocean, are major concerns in coral reef management. While biological and ecological knowledge of COTS has been accumulating since the 1960s, little is known about its associated bacteria. The aim of this study was to provide fundamental information on dominant COTS-associated bacteria through a multifaceted molecular approach.MethodsA total of 205 COTS individuals from 17 locations throughout the Indo-Pacific Ocean were examined for the presence of COTS-associated bacteria. We conducted 16S rRNA metabarcoding of COTS to determine the bacterial profiles of different parts of the body, and generated a full-length 16S rRNA gene sequence from a single dominant bacterium, which we designated COTS27. We performed phylogenetic analysis to determine the taxonomy, screening of COTS27 across the Indo-Pacific, FISH to visualize it within the COTS tissues, and reconstruction of the chromosome from the hologenome sequence data.ResultsWe discovered that a single bacterium exists at high densities in the subcuticular space in COTS forming a biofilm-like structure between the cuticle and the epidermis. COTS27 belongs to a clade that presumably represents a distinct order (so-called marine spirochetes) in the phylum Spirochaetes and is universally present in COTS throughout the Indo-Pacific Ocean. The reconstructed genome of COTS27 includes some genetic traits that are probably linked to adaptation to marine environments and evolution as an extracellular endosymbiont in subcuticular spaces.ConclusionsCOTS27 can be found in three allopatrically speciated COTS species, ranging from northern Red Sea to the Pacific, implying that symbiotic relationship arose before the speciation (approximately 2 million years ago). The universal association of COTS27 with COTS and nearly mono-specific association at least with the Indo-Pacific COTS potentially provides a useful model system for studying symbiont-host interactions in marine invertebrates.

scholarly journals Stress, novel sex genes, and epigenetic reprogramming orchestrate socially controlled sex change

2019 ◽  
Vol 5 (7) ◽  
pp. eaaw7006 ◽  
Author(s):  
Erica V. Todd ◽  
Oscar Ortega-Recalde ◽  
Hui Liu ◽  
Melissa S. Lamm ◽  
Kim M. Rutherford ◽  
...  
Keyword(s):  
Developmental Process ◽  
Molecular Level ◽  
Sex Change ◽  
Epigenetic Reprogramming ◽  
Stress Axis ◽  
Specific Gene ◽  
Gene Encoding ◽  
Epigenetic Machinery ◽  
Male Sex ◽  
Early Developmental

Bluehead wrasses undergo dramatic, socially cued female-to-male sex change. We apply transcriptomic and methylome approaches in this wild coral reef fish to identify the primary trigger and subsequent molecular cascade of gonadal metamorphosis. Our data suggest that the environmental stimulus is exerted via the stress axis and that repression of the aromatase gene (encoding the enzyme converting androgens to estrogens) triggers a cascaded collapse of feminizing gene expression and identifies notable sex-specific gene neofunctionalization. Furthermore, sex change involves distinct epigenetic reprogramming and an intermediate state with altered epigenetic machinery expression akin to the early developmental cells of mammals. These findings reveal at a molecular level how a normally committed developmental process remains plastic and is reversed to completely alter organ structures.

scholarly journals Follistatin Regulates Germ Cell Nest Breakdown and Primordial Follicle Formation

Endocrinology ◽  
2010 ◽  
Vol 152 (2) ◽  
pp. 697-706 ◽  
Author(s):  
Fuminori Kimura ◽  
Lara M. Bonomi ◽  
Alan L. Schneyer
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Ovarian Function ◽  
Primordial Follicle ◽  
Biochemical Properties ◽  
The Body ◽  
Protein Isoforms ◽  
Primordial Follicles ◽  
Reduced Rate ◽  
Regulatory Functions

Abstract Follistatin (FST) is an antagonist of activin and related TGFβ superfamily members that has important reproductive actions as well as critical regulatory functions in other tissues and systems. FST is produced as three protein isoforms that differ in their biochemical properties and in their localization within the body. We created FST288-only mice that only express the short FST288 isoform and previously reported that females are subfertile, but have an excess of primordial follicles on postnatal day (PND) 8.5 that undergo accelerated demise in adults. We have now examined germ cell nest breakdown and primordial follicle formation in the critical PND 0.5–8.5 period to test the hypothesis that the excess primordial follicles derive from increased proliferation and decreased apoptosis during germ cell nest breakdown. Using double immunofluorescence microscopy we found that there is virtually no germ cell proliferation after birth in wild-type or FST288-only females. However, the entire process of germ cell nest breakdown was extended in time (through at least PND 8.5) and apoptosis was significantly reduced in FST288-only females. In addition, FST288-only females are born with more germ cells within the nests. Thus, the excess primordial follicles in FST288-only mice derive from a greater number of germ cells at birth as well as a reduced rate of apoptosis during nest breakdown. These results also demonstrate that FST is critical for normal regulation of germ cell nest breakdown and that loss of the FST303 and/or FST315 isoforms leads to excess primordial follicles with accelerated demise, resulting in premature cessation of ovarian function.

181 CHANGES IN THE BODY CONDITION STATUS OF DONOR MARES THROUGHOUT THE BREEDING SEASON AND THEIR RELATIONSHIP WITH REPRODUCTION TRAITS

2010 ◽  
Vol 22 (1) ◽  
pp. 249
Author(s):  
P. G. Rodrigues ◽  
C. M. Raymundo ◽  
M. C. M. G. Miranda ◽  
J. B. Bastos ◽  
J. C. DeSouza
Keyword(s):  
Breeding Season ◽  
Body Condition ◽  
Recovery Rate ◽  
Fixed Effects ◽  
Mixed Model ◽  
Body Condition Score ◽  
Follicular Phase ◽  
The Body ◽  
Embryo Recovery ◽  
Follicle Diameter

The objective was to investigate the relationship between changes in body condition on reproductive traits of donor mares in an embryo collection program. Fifty-six non-pregnant mares, 3 to 18 years old, were studied from August 2008 through April 2009. Body condition score (BC; 1-9 scale, thin to obese) was estimated monthly. Body weight and tail and rib s.c. fat depths (SF) were measured monthly. SF was determined by ultrasound. Dominant follicle diameter (DF) was measured daily during the follicular phase. Mares were artificially inseminated and embryo transfers were conducted 6 d after ovulation. Analyses were performed with SAS® (SAS Institute Inc., Cary, NC, USA). Age classes were as follows: age 1, 3 to 6.9 (n = 17); age 2, 7 to 12.9 (n = 25), and age 3, ≥13 years (n = 14). Months in experiment were T1 to T6. BC classes were as follows: B1, <6.5; B2, 6.5 to 6.9; B3, 7.0 to 7.5; and B4, >7.5. Embryo recovery rate was compared by chi square. Effects of month and age on BC, weight, and SF were analyzed by a mixed model. Age, BC, and month fixed effects on DF diameter were analyzed by ANOVA with mare within class as the error term. Means were compared by contrasts. BC was higher (P = 0.02) in older mares (6.78 ± 0.2 and 6.93 ± 0.2 in age 1 and age 2 v. 7.25 ± 0.2 in age 3) and increased (P = 0.009) with time (from 6.79 ± 0.20 to 7.42 ± 0.26 for T1 to T6, respectively). Weight (kg) was not associated with age but increased (P = 0.03) throughout the experiment. Tail fat increased with age (P = 0.04) and decreased with increasing months on experiment (P = 0.02). DF diameter increased daily through the follicular phase (P < 0.0001) and was smaller (P < 0.05) in mares with lower body condition (33.80 ± 0.31 in BC1 v. 34.17 ± 0.31 mm in BC4). DF diameter decreased (P < 0.01) with month on study. Embryo recovery rate was not affected by age or BC but was lower (P = 0.003) in mares that ovulated follicles smaller than 40 mm compared to mares ovulating follicles greater than 40 mm. BC above 6.5 was associated with higher embryo recovery rate, which was, in turn, correlated positively with DF diameter. Thus, our results support the use of BC scoring to predict performance in equine embryo transfer programs. Body condition scoring was not a good indicator of SF under the current experimental conditions because SF decreased during the breeding season. BC scoring may indicate lean tissue gain, which may be a better indicator of reproductive efficiency in mares. FAPEMIG, CAPES, Haras El Far.

Zinc and selenium combination treatment protected diabetes-induced testicular and epididymal damage in rat

2020 ◽  
Vol 39 (9) ◽  
pp. 1235-1256 ◽  
Author(s):  
C Sahu ◽  
DK Dwivedi ◽  
GB Jena
Keyword(s):  
Glutathione Peroxidase ◽  
Germ Cell ◽  
Combination Treatment ◽  
Cell Damage ◽  
Combined Treatment ◽  
Tunel Assay ◽  
The Body ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Feed Water ◽  
Related Factor

Diabetes increases the possibility of germ cell damage, hypogonadism, and male infertility. Diabetic condition negatively impacts zinc (Zn) and selenium (Se) levels in the body. Zn and Se are among the most important trace elements involved in the regulation of redox reaction, antioxidants enzymes activities, and DNA expression in a germ cell. The present study aimed to elucidate the combined effects of Zn and Se treatment on diabetes-induced germ cell damage in male Sprague Dawley rats. Type 1 diabetes was induced by the single intraperitoneal (i.p.) injection of streptozotocin (55 mg/kg). Zn (3 mg/kg, i.p.) and Se (0.5 mg/kg, i.p.) were administered daily for 8 consecutive weeks. All the animals were provided with normal feed and water throughout the study. The effects on germ cell damage were evaluated by body weight, feed-water intake, organ weight, sperm count, motility, sperm head morphology, biochemical analysis, histology, immunohistochemistry, halo assay, germ cell comet assay, testes terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end-labeling (TUNEL) assay, sperm TUNEL assay, serum protein pattern analysis, and subcellular analysis using transmission electron microscopy. Further, the expressions of nuclear erythroid-derived related factor 2, catalase, glutathione peroxidase 4, and glutathione peroxidase 5 were carried out to ascertain the mechanism of protection. The present results demonstrated that 8 weeks combined treatment of Zn (3 mg/kg, i.p.) and Se (0.5 mg/kg, i.p.) reduced diabetes-induced germ cell damage. This study further highlighted that Zn and Se combination treatment might be a better strategy for the germ cell protection in diabetes and deserve further investigation.

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