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At least 19 recordsLinked to original sources
PubMed2026

Age-related differences in semen quality in Holstein-Friesian bulls: a paired within-bull comparison of early and mature reproductive stages.

Genomic selection has changed dairy cattle breeding by increasing the use of young bulls for artificial insemination and shortening the reproductive lifespan of sires. Under these conditions, semen quality at the beginning of commercial use has become an important practical issue. Semen samples from 39 fertile Holstein-Friesian bulls used for commercial AI were collected between 2013 and 2016, during the introduction of genomic selection in Poland. This paired within-bull study compared semen collected from the same bulls at an early reproductive stage (13-20 months; young bulls, YB) and at full maturity (5-6 years; mature bulls, MB). The evaluation included conventional ejaculate traits, CASA-derived motility and kinematic descriptors, mtDNA copy number, and mitochondrial content per sperm cell. Importantly, all ejaculates met the quality requirements for commercial insemination. Ejaculate volume, sperm concentration, mitochondrial DNA copy number, and mitochondrial content did not differ significantly between age groups. The CASA-derived sperm movement profile, in contrast, differed with age. Semen from young bulls showed a higher proportion of progressively motile spermatozoa, whereas semen from mature bulls showed higher velocity-related parameters, including VSL, VCL, and STR. These findings indicate that bull age mainly affected sperm movement characteristics rather than semen output or mitochondrial content. Overall, the results support the use of young bulls in artificial insemination programs and show that age-related differences in semen quality are expressed mainly through changes in the post-thaw sperm motility and kinematic profile.

Animals↗
PubMed1978

Histochemical studies on the peroxidase localization in the rat ovary and uterus during various reproductive stages.

A histochemical study has been made of peroxidase changes in rat ovary and uterus during different developmental stages of the normal and pregnant rats. The peroxidase was found to be present in the corpus luteum of the ovary of both normal and pregnant rats as well as in the allantochorionic placenta, while the growing follicles in the immature and mature rat ovary showed no activity. The possible physiological significance of the peroxidase changes in relation to luteal steroidogenesis has been discussed.

Age Factors↗
PubMed1977

Pituitary responsiveness to synthetic LH-RH and pituitary LH content at various reproductive stages in the sheep.

In sheep the basal concentration of LH in jugular vein plasma was significantly higher during the first 50 days of gestation in late pregnancy or at parturition. The pituitary response to a single i.v. injection of 200 microng synthetic LH-RH was determined at different stages of gestation and compared with that of anoestrous and cyclic sheep. Pituitary response to LH-RH decreased progressively with advancing gestation: by 56 days after mating the response had declined to 35% and by parturition to 14% of the value in anoestrous sheep. The pituitary response to LH-RH increased after parturition and the pattern of recovery differed in non-lactating and lactating sheep. By 63 days postpartum the response to LH-RH in non-lactating and lactating animals had returned to values similar to those in sheep during anoestrus and sheep during the luteal phase of the oestrous cycle. A decrease in pituitary responsiveness during pregnancy was associated with a decrease in pituitary content of LH. The quantity of LH released in response to a standard injection of LH-RH was linearly related to pituitary LH content.

Animals↗
PubMedDate not supplied

Activity of noradrenergic neurons of medial-basal hypothalamus of female rabbits in some stages of reproduction.

Activity of noradrenergic neurons of medial-basal hypothalamus of female rabbits in some stages of reproduction. Acta Physiol. Pol., 1978, 29 (2): 111--115. The differences were found in the activity of noradrenergic neurons of medial-basal hypothalmus (MBH) estimated by the analysis of metabolism of intraventricularly infused 3H-noradrenaline (3H-NA) in various stages of reproduction in female rabbits. The gonadal hormones and especially 17beta-estradiol seem to be involved in this activity. The rapid disappearance of 3H-NA from MBH, found immediately after mating, implicates an involvement of noradrenaline in the process of Gn-RHs release form the rabbit hypothalamus.

Animals↗
PubMed1977

Trypanosoma musculi infections in normocomplementemic, C5-deficient, and C3-depleted mice.

The role of complement in host resistance to infection with Trypanosoma musculi was studied in normal, C5-deficient, and C3-depleted mice. Infections in normocomplementemic strains (CBA and B10.D2/n) were generally similar to those in strains genetically deficient in C5 (A and B10.D2/o). There were no differences in inhibition of reproduction, duration of infection, persistence of parasites in the kidneys, or resistance to reinfection. However, peak parasitemias in B10.D2/o mice were slightly greater than in B10.D2/n mice. In addition, B10.D2/o mice had slightly decreased serum levels of C1 early in the course of infection and of C3 early during the elimination of adult forms. These components were unchanged or increased in infections of B10.D2/n. Depletion of C3 and late-acting components in B10.D2/n mice by treatment with cobra venom factor during the reproductive stage of infection resulted in an increase of reproductive forms before the apparent development of ablastic immunity as well as slightly greater peak parasitemias when compared with those of untreated controls. Cobra venom factor treatment of B10.D2/o mice during the reproductive stage did not alter the course of infection. Cobra venom factor treatment of C3H mice during the adult stage prolonged infections by interfering with parasite elimination. It is concluded that complement-mediated lysis is not involved in control of T. musculi. It is not clear whether a C3-dependent function such as phagocytosis may facilitate elimination of the parasites. The major difference in degree of parasitemias among the various strains of mice studied is due to genetic factors rather than the levels of C3, C5, or late-acting complement components.

Animals↗
PubMed1978

The effects of enzyme concentration on the kinetic behavior of adrenal 21-hydroxylase and 11beta-hydroxylase in the pregnant rat.

Experiments were designed to study the kinetic behavior of 21-hydroxylase and 11beta-hydroxylase as a function of enzyme concentration (Et) during proestrus, dasy 5 (D5), 12 (D12), and 22 (D22) of pregnancy, and within 24 h post-partum. The enzymes were prepared from rat adrenal microsomes and mitochondria, respectively. The experiments consisted of measuring the initial velocity of each reaction for a series of substrate concentrations at three fixed Et. Double reciprocal plots were constructed and the slope (Km/Vmax) of each line estimated. Variation in the value of the slope as a function of enzyme dilution would predict the presence of an endogenous effector. The kinetic behavior of 21-hydroxylase was not altered throughout the range of Et (10-100 microgram protein) at any of the reproductive stages. In contrast, kinetic behavior of 11beta-hydroxylase was clearly dependent upon Et. Dilution of the enzyme preparation (25-200 microgram of protein) increased the slope of the double reciprocal plot at all reproductive stages, thus suggesting that an activator substance may be present within the mitochondrial preparation. A secondary plot of the slope (Km/Vmax) versus Et described a power function (Km/Vmax = a [Et]b) with the greatest rate of change in Km/Vmax occurring at low values of Et. The rate of change in Km/Vmax per mg rise in mitochondrial protein at all dilutions of enzyme was greatest for proestrus and post-partum, followed by D22 greater than D12 greater than D5. In addition, repeated washing of the enzyme preparation at 4 degrees C increased Km/Vmax to a greater extent at all Et than did the control preparation. These findings suggest the presence of a diffusible endogenous activator of 11beta-hydroxylase whose influence decreases markedly at D5 and D12. On the other hand, there is no evidence to suggest the presence of a diffusible endogenous effector for 21-hydroxylase.

Adrenal Glands↗
PubMed1979

The variation of the mean spinability of human cervical mucus throughout the various stages of reproductive life. Automatic measurement and statistical study.

The evolution of the mean spinability value of human cervical mucus was studied by means of an automatic device throughout the menstrual cycle and pregnancy and during and after the onset of menopause. The automatic measurement brings to light the major drawbacks presented by manual methods: values previously obtained should be considered as underestimated. The mean spinability value recorded from cyclic mucus exhibits a very significant increase at mid-cycle. Graphical analysis demonstrates that only small differences in the mean spinability value occur as pregnancy proceeds. A progressive and regular decrease in the mean spinability value can be recorded from the very beginning of the menopause. However, the spinability values observed in premenopausal mucus are noticeably higher than those recorded after the onset of the menopause. The numeric data furnished by the automatic measurement are discussed in terms of statistics.

Cervix Mucus↗
PubMed2026

Evolutionary Conservation and Reproductive Expression of ABC Transporter Genes in Two Sphenomorphus Skinks.

ATP-binding cassette (ABC) transporters represent one of the largest membrane protein superfamilies in vertebrates, playing essential roles in translocating diverse substrates across membranes. However, knowledge of ABC transporter genes in reptiles remains limited. In this study, we conducted a comprehensive genome-wide identification and characterization of the ABC gene family in oviparous Sphenomorphus incognitus and viviparous Sphenomorphus indicus. A total of 45 ABC genes were identified in each species and classified into seven subfamilies (ABCA-ABCG). Comparative and phylogenetic analyses revealed a generally conserved gene repertoire, with limited duplication events observed mainly in the ABCA and ABCG subfamilies, whereas other subfamilies (e.g., ABCE, ABCF, and ABCD) remained highly conserved. Interestingly, a lineage-specific duplication of ABCC2 was identified in lizards. Oviductal expression profiling revealed distinct temporal patterns of ABC gene expression across reproductive stages. Several genes, including ABCG1, ABCC3, and ABCD4, exhibited conserved expression trajectories across both species, suggesting shared transcriptional regulation. In contrast, ABCA1, ABCB1, and ABCG2 showed species-specific expression patterns, indicating regulatory divergence between the two lizard species. Overall, ABC gene expression was more dynamic in S. incognitus than in S. indicus. In summary, although the ABC transporter family is structurally conserved, it exhibits lineage-specific evolutionary changes and divergent transcriptional regulation in lizard oviducts. This study provides a foundation for understanding the diversity and regulation of ABC transporter genes in reptiles.

Animals↗
PubMed2025

Replacement of chromosome 3D with Thinopyrum chromosome 3St led to increased drought tolerance during the flowering stage in wheat.

The stable 3St(3D) substitution line offers promising genetic potential for improving drought tolerance in wheat during critical reproductive stages. The flowering stage is highly susceptible to drought, which significantly reduces wheat grain yield globally. Low genetic diversity in wheat further limits the discovery of optimal gene variants for breeding climate-resilient varieties. The substitution of chromosome 3D by a group 3 chromosome pair from Thinopyrum intermedium × Th. ponticum artificial hybrid was identified using in situ hybridization and genotyping-by-sequencing. This homoeologous substitution showed good functional compensation for grain yield and fertility, similar to the wheat parents ('Mv9kr1' and 'Mv Karizma') in field and greenhouse trials. The substitution line exhibits a semidwarf phenotype due to the Rht8 and Rht2 dwarfing alleles. Automated shoot phenotyping after a 10-day water withdrawal at flowering revealed efficient water preservation allowing to maintain photosynthetic functions, sustained photosynthetic activity, and less chlorophyll degradation, indicated by Normalized Difference Vegetation Index (NDVI) and modified Normalized Difference Index (mND705) values and moderate level of protective functions shown by the expression of stress-related genes. Compared to the wheat parents, the substitution line developed thicker roots with increased volume under drought, resulting in a lower surface-to-volume ratio. This may enhance water storage efficiency and help reduce yield loss under drought conditions.

Triticum↗
PubMed2026

Proteomic profiling of the aqueous extract from the antennal gland of the Pacific white shrimp, Litopenaeus vannamei.

The antennal gland (AnG) of decapod crustaceans has been proposed as a potential source of bioactive molecules involved in chemical communication; however, its protein composition remains largely unexplored. Here, we present the first reference proteomic map of the aqueous extract from the antennal gland of the Pacific white shrimp Litopenaeus vannamei. Protein extracts from immature and mature females were analyzed using an integrated workflow combining one-dimensional SDS-PAGE, reverse-phase high-performance liquid chromatography (RP-HPLC), and nanoLC-tandem mass spectrometry. Electrophoretic and chromatographic analyses revealed a high degree of qualitative similarity between reproductive stages. SDS-PAGE resolved six major protein bands (∼227, 166, 77, 42, 35, and 17 kDa), most comprising multiple co-migrating proteins as revealed by LC-MS/MS. Hemocyanin was identified as the predominant protein and was detected across several electrophoretic bands. Additional proteins were associated with innate immunity, including β-1,3-glucan-binding protein and coagulable hemolymph protein; reproductive processes, including vitellogenin, spermatogonial stem-cell renewal factor, farnesoic acid O-methyltransferase, estrogen sulfotransferase, and prostaglandin reductase 1; as well as energy metabolism, protein homeostasis, cytoskeletal organization, and intracellular trafficking. Because several identified proteins are widely distributed or known hemolymph components, their detection cannot be assumed to reflect AnG-specific expression or function. Collectively, these findings establish a molecular reference for the L. vannamei AnG and reveal protein components associated with multiple physiological processes. This dataset provides a proteomic framework for future comparative and functional studies aimed at elucidating antennal gland physiology and experimentally evaluating the potential involvement of proteinaceous or peptide-based molecules in chemical communication in decapod crustaceans.

Animals↗
PubMed2026

Cultivar-dependent regulation of cytokinin biosynthesis in wheat: developmental expression of TaIPT genes and hormonal crosstalk during reproductive development.

BACKGROUND: Cytokinins are key regulators of plant growth, reproductive development, and yield formation. In cereals, cytokinin biosynthesis is catalyzed by isopentenyltransferase (IPT) enzymes, yet the genomic organization and developmental regulation of IPT genes in polyploid wheat remain incompletely understood, especially at the cultivar level. RESULTS: Here, we present an integrated genomic, transcriptional, and hormonal analysis of the TaIPT gene family during vegetative and reproductive development in two wheat cultivars, awnless Kontesa and awned Ostka. Genome-wide analysis identified nine core TaIPT genes represented by 25 homoeologs distributed across the A, B, and D subgenomes, for which a unified nomenclature was established. Phylogenetic analysis resolved TaIPTs into conserved evolutionary clades corresponding to ATP/ADP-dependent and tRNA-dependent IPT groups. Expression profiling revealed distinct spatial and temporal patterns of TaIPT transcription across roots, leaves, inflorescences, and developing spikes. Several TaIPT genes showed enhanced expression during early reproductive stages, coinciding with dynamic changes in cytokinin concentrations. Comparative analyses revealed cultivar-specific expression and co-variation patterns, with Kontesa displaying more compartmentalized TaIPT expression and Ostka showing coordinated activation of multiple TaIPT genes during early grain development. Hormone profiling further indicated stage-dependent associations between TaIPT expression, cytokinin metabolism, and the balance between cytokinins and abscisic acid. These relationships are interpreted as correlative and provide a framework for future functional testing rather than direct evidence of causality. CONCLUSIONS: Together, these results provide a cultivar-focused framework for understanding the organization and regulation of cytokinin biosynthesis genes in wheat. The data highlight cultivar-dependent TaIPT expression patterns and their association with cytokinin dynamics during reproductive development, while also identifying the need for homoeolog-specific and functional validation. This study establishes a foundation for future research on cytokinin-mediated regulation of wheat growth and grain development.

Triticum↗
PubMed2022

Sex Differences in Human Immunodeficiency Virus Persistence and Reservoir Size During Aging.

BACKGROUND: Sex differences in human immunodeficiency virus (HIV) reservoir dynamics remain underexplored. METHODS: Longitudinal samples from virally suppressed midlife women (n = 59, median age 45 years) and age-matched men (n&#x2005;=&#x2005;31) were analyzed retrospectively. At each time point, we measured sex hormones (by means of enzyme-linked immunosorbent assay) and cellular HIV DNA and RNA (by means of digital droplet polymerase chain reaction). Number of inducible HIV RNA+ cells, which provides an upper estimate of the replication-competent reservoir, was quantified longitudinally in a different subset of 14 women, across well-defined reproductive stages. Mixed-effects models included normalized reservoir outcomes and sex, time since antiretroviral therapy (ART) initiation, and the sex-by-time interaction as predictors. RESULTS: At ART initiation, women and men had median (interquartile range [IQR]) CD4+ T-cell counts of 204/&#x3bc;L (83-306/&#x3bc;L) versus 238/&#x3bc;L (120-284/&#x3bc;L), respectively; median ages of 45 (42-48) versus 47 (43-51) years; and median follow-up times of 79.2/&#x3bc;L (60.5-121.1/&#x3bc;L) versus 66.2/&#x3bc;L (43.2-80.6/&#x3bc;L) months. We observed a significant decline of total HIV DNA over time in both men and women (P&#x2005;<&#x2005;.01). However, the rates of change differed significantly between the sexes (P&#x2005;<&#x2005;.01), with women having a significantly slower rate of decline than men, more pronounced with age. By contrast, the levels of inducible HIV RNA increased incrementally over time in women during reproductive aging (P&#x2005;<&#x2005;.01). CONCLUSIONS: In contrast to men, in whom the HIV reservoir steadily declines with aging, the HIV reservoir in women is more dynamic. Total HIV DNA (including intact and defective genomes) declines more slowly in women than in men, while the inducible HIV RNA+ reservoir, which is highly enriched in replication-competent virus, increases in women after menopause.

Aging↗
PubMed1979

Cyclic changes in ciliation, secretion and cell height of the oviductal epithelium in women.

Oviducts were obtained from women who elected to undergo sterilization either during a normal menstrual cycle, after the first trimester of pregnancy, or in the puerperium. The percent of ciliated cells, cell height and morphology of the fimbria and ampulla were determined and correlated with the stage of the reporductive cycle and plasma levels of the ovarian steroids. Mature ciliated and secretory cells were observed only at mid-cycle. Atrophy, deciliation and loss of secretory activity coincided with elevated levels of serum progesterone. These degenerative processes continued during pregnancy. Ciliation, hypertrophy, and restoration of secretory activity occurred when serum progesterone was essentially undetectable and estradiol relatively low. During each menstrual cycle the secretory cells were observed to undergo a complete cycle of dedifferentiation-differentiation, whereas 10--12% of the ciliated cells lost and regenerated their celia. Ciliogenic cells were frequently present in the epithelium obtained from women in the mid-follicular phase. Fibrous granules, deuterosomes, procentrioles and ciliary buds were observed in the apex of these cells. Plasma levels of estradiol were higher during periods of atrophy and deciliation than they were during periods of hypertrophy and reciliation. It appears that the serum levels of estradiol were adequate to maintain a mature epithelium at all the reproductive stages included in this study. However, progesterone, when present, blocked the growth-promoting effect of estradiol in the oviduct.

Cilia↗
PubMed1975

Production of ethylene and other volatiles and changes in cellulase and laccase activities during the life cycle of the cultivated mushroom, Agaricus bisporus.

Nine volatile hydrocarbons, as well as methyl chloride, carbonyl sulphide and carbon disulphide, have been identified by mass spectrometry as products of Agaricus bisporus in the compost used in comerical mushroom beds. Of these, only ethylene showed a pattern of production that could be correlated with developmental phases of the crop, high levels being produced whenever fruit bodies were rapidly enlarging. In laboratory flask cultures, under controlled conditions, high levels of ethylene occurred whenever young fruit bodies entered the expansion phase. The enhanced rate of ethylene production continued over several days, irrespective of whether fruit bodies were removed. Production occurred within the colonized compost; no ethylene was evolved by the fruit body itself. When the first fruit bodies expanded, either in beds or culture flasks, laccase levels in the compost fell and those of a beta-1,4-glucanase (cellulase) rose. The enzyme switch occurred once only, during maturation of the first fruit bodies, whereas an elevated ethylene production was associated with each occasion when fruit body maturation took place. The low level of laccase and high of cellulase characterized the whole of the reproductive stage of A. bisporus, whereas the phasic periods of high ethylene production distinguished between periods of fruit body maturation and intervening resting periods.

Agaricales↗
PubMed1978

Rabbit ovarian protein kinases. I. Effect of an ovulatory dose of human chorionic gonadotropin or luteinizing hormone on the subcellular distribution of follicular and luteal protein kinases.

Studies on the subcellular distribution of protein kinase activity in popped estrous follicles from rabbit ovaries revealed that 15% of the total cellular protein kinase activity was compartmentalized in the nuclear, mitochondrial, and microsomal fractions. About 50% of the particulate protein kinase activity was unaffected by the heat-stable protein kinase inhibitor and was thus cAMP-independent. The majority of cellular protein kinase activity was identified in the 105,000 X g supernatant fraction as cAMP-dependent. hCG- or coital-induced ovulation and subsequent corpus luteum (CL) formation, and hCG-induced luteal regression promoted changes and a redistribution of protein kinase activity among the subcellular fractions. In follicles, hCG promoted a transient decline of nuclear protein kinase activity as well as transient increases of the relative amount of protein kinases localized in the microsomal fractions before ovulation. In CL induced by a fertile mating, the specific activity as well as the total amount of protein kinases in the nuclear fraction were reduced 2-fold. Mitochondrial protein kinase activity from CL of pseudopregnancy and pregnancy was reduced 2-fold. The relative amount of protein kinase activity in microsomes of CL was increased 2-fold, but the specific activity was not affected. hCG-induced luteal regression resulted in a transient decline of the nuclear protein kinase activity in CL of 4-day pseudopregnant rabbits. In interstitial tissue, the specific activity of the nuclear protein kinase was increased over luteal levels, the mitochondrial-specific protein kinase remained at the reduced luteal levels, and the microsomal and cytosol protein kinase specific activities increased 2-fold. Studies with the heat-stable protein kinase inhibitor revealed that the hCG- or coital-induced redistribution of intracellular protein kinase affected both the cAMP-dependent and cAMP-independent activity to a similar degree and no changes of the relative distribution of cAMP-dependent vs. cAMP-independent activity were observed. These results indicate that the intracellular distribution and enzymatic activity of cAMP-dependent protein kinases in ovarian structures are subject to regulation by LH (hCG) and depend upon the various reproductive stages of the rabbit.

Animals↗
PubMed1978

Rabbit ovarian protein kinases. II. Effect of an ovulatory dose of human chorionic gonadotropin or luteinizing hormone on the multiplicity of follicular and luteal protein kinases.

DEAE-cellulose chromatography of the 105,000 X g supernatant fraction (cytosol) obtained from popped estrous rabbit follicles revealed the presence of a single form of cAMP-dependent protein kinase, designated protein kinase 3. The iv injection of an ovulatory dose of hCG to estrous rabbits promoted the appearance of a second, transient peak of cytosol cAMP-dependent protein kinase, protein kinase 1. Protein kinase 1 was detected within 10 min of hCG administration but had regressed to undetectable levels by 24 h in corpora lutea (CL) of pseudopregnancy and by 72 h in CL of pregnancy. Ovulation and subsequent CL formation were accompanied by the appearance of a third form of cAMP-dependent protein kinase, designated protein kinase 2. Protein kinase 2 was present within 2 h after hCG administration and persisted as a major form of cytosol cAMP-dependent protein kinase throughout the life span of CL. All three forms of protein kinase were inhibited by the heat-stable protein kinase inhibitor from rabbit skeletal muscle, possessed cAMP-binding activity, and were markedly stimulated by 10(-7) M cAMP. The activity of protein kinase 3 in CL of pregnancy, in corpora albicantia, and in interstitial tissue was markedly greater than that in follicles or in CL of pseudopregnancy, while the activity of protein kinase 2 remained relatively constant throughout the luteal life span. The iv injection of a luteolytic dose of hCG to 4-day pseudopregnant rabbits promoted no alterations of the protein kinase elution profile upon DEAE-cellulose chromatography of the luteal cytosol obtained 10 min to 3 days post-hCG injection. However, with dedifferentiation of corpora albicantia into interstitial tissue, the cAMP dependency of protein kinase 2 was reduced. The results indicate that the enzymatic activity and multiplicity of cAMP-dependent protein kinases in the cytosol of ovarian structures are subject to regulation by LH (hCG) and depend upon the various reproductive stages of the rabbit.

Animals↗