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PubMed1989

Blood flow in the ovaries and ovarian follicles of Romanov and Préalpes-du-Sud ewes.

Radioactive microspheres (15 microns diameter) were used to measure capillary blood flow rates in the ovaries and ovarian follicles (Qf) in high fecund Romanov and low fecund Préalpes-du-Sud ewes at the preovulatory stage of the oestrous cycle. Additionally, assessments of the percentage of arterial blood passing through ovarian arterio-venous anastomoses were obtained. The mean +/- s.e.m. Qf per unit volume of theca [ml/min) x 10(4)/mm3) for non-atretic follicles in Romanov ewes was significantly greater (P less than 0.05) than that in Préalpes ewes (365.8 +/- 42.4, n = 19, compared with 241.3 +/- 30.1, n = 14). For each breed, the mean Qf value for non-atretic follicles was 8-10 times greater than that for atretic follicles. In Romanov ewes, total Qf [ml/min) x 10(4) and Qf per unit volume of theca was greatest in small-sized follicles (3.1-5.0 mm) while in Préalpes ewes, maximum flow was attained in larger-sized follicles (5.1-7.0 mm). The elevated Qf in small-sized follicles in Romanov ewes may be conducive to more follicles achieving maturation at a smaller diameter in this breed than occurs in the Préalpes ewes. The absence of flow through ovarian arterio-venous anastomoses in the Romanov, but not in the Préalpes, ewes suggests different mechanisms for controlling the distribution of the total ovarian blood supply in the 2 breeds.

Animals↗

PubMed1994

Effect of thyroidectomy upon seasonality in rams.

Experiments were conducted to examine whether seasonal breeding patterns of male sheep are abrogated by thyroidectomy. In Expt 1, Welsh Mountain rams were thyroidectomized in early autumn (September) and then maintained on either 16 h light: 8 h dark (long days; n = 6) or 8 h light: 16 h dark (short days; n = 6) for 8 months. Intact rams (n = 6 per group) were also housed in long or short days, or in natural photoperiods. Results were similar in animals housed on long or short days. In thyroidectomized rams, plasma FSH concentrations and scrotal circumference were maintained at values typical of the breeding season throughout the investigation, whereas in intact animals both reached a nadir in December and January. In Expt 2, a further 11 rams were thyroidectomized in March and, together with 23 intact animals, were maintained thereafter in natural photoperiods. In control rams, scrotal circumference increased slowly between May and September, whereas in thyroidectomized animals the circumference increased rapidly in the first 4 weeks following thyroidectomy (3.7 +/- 0.7 cm), with a further increase (5.9 +/- 1.0 cm) in the next 4 weeks. The scrotal circumference of thyroidectomized rams was therefore significantly (P < 0.01) greater than that in intact animals between April and August. Plasma FSH concentrations were significantly (P < 0.01) higher in thyroidectomized than in control rams by two weeks after surgery. These results indicate that thyroidectomy overcomes the seasonal (or photorefractory) inhibition of reproductive activity in rams and supports a key role for thyroid hormones in the expression of seasonal patterns of breeding activity.

Animals↗

PubMed1988

Environmental and hormonal factors in seasonal breeding in free-living male Indian rose-ringed parakeets (Psittacula krameri).

Seasonal changes in testicular activity, plasma luteinizing hormone (LH), estradiol (E2), testosterone (T), and 5 alpha-dihydrotestosterone (5 alpha-DHT) were related to pair bond formation, nest building, nest defense, and parental behavior in free-living Indian rose-ringed parakeets (Psittacula krameri) in northwest India. Spermatozoa production occurred between January and March when daylengths were short (10-12 hr) and ambient temperature was seasonally low (8-20 degrees C). At other times of the year the testes were regressed. Plasma LH levels increased during the prebreeding period (September-December) when the birds were forming pairs and selecting or defending nest sites. Plasma LH levels increased further between January and March and decreased to seasonal low values during the post breeding period between April and June when the birds were caring for young. Concentrations of plasma androgens and estrogens were similar during the prebreeding and postbreeding phases of the breeding cycle. During the breeding period, the ratios between plasma 5 alpha-DHT and testosterone and between plasma estradiol and testosterone increased. It is proposed that the absence of marked seasonal changes in plasma steroid levels is related to nest defense behavior which occurs during the prebreeding, breeding, and postbreeding phases of the breeding cycle. Winter breeding makes it possible for the parakeets to avoid competition with other birds for nesting sites, to avoid fledging young during the monsoon period, and to take advantage of the winter pea crop which provides the female with extra nutrients for egg production.

Animals↗

PubMed1981

Stimulation of pituitary and testicular functions with LH-RH agonist or pulsatile LH-RH treatment in the rhesus monkey during the non-breeding season.

Out-of-season male rhesus monkeys were used to compare the effectiveness of pulsatile treatment with LH-RH and administration of LH-RH agonist on testicular function. Treatment with LH-RH agonist (1.0 microgram Hoe 766/day) for 11 weeks resulted in partial stimulation of pituitary and testicular functions. The pituitary LH response to the agonist increased during treatment. Testosterone levels were stimulated to within the normal range and 2 of the 4 treated monkeys produced ejaculates, but sperm counts were below normal. Pulsatile treatment with LH-RH (100 ng every 96 min for 7 days alternating with LH-RH agonist treatment for 7 days) in 2 monkeys induced full testicular activity after 7 weeks. Ejaculations were induced at a time when the rhesus monkey is normally sexually inactive. Seminal characteristics at the end of treatment were similar to values in the normal breeding season. In samples collected from one monkey over a 24-h period before treatment there were no LH spikes and very low testosterone levels. During pulsatile LH-RH treatment distinct LH and testosterone spikes occurred, comparable to those in the breeding season.

Animals↗

PubMed2006

Genetic variation and relationships among eight Indian riverine buffalo breeds.

Twenty-seven microsatellite loci were used to define genetic variation and relationships among eight Indian riverine buffalo breeds. The total number of alleles ranged from 166 in the Toda breed to 194 each in the Mehsana and the Murrah. Significant departures from the Hardy-Weinberg equilibrium were observed for 26 locus-breed combinations due to heterozygote deficiency. Breed differentiation was analysed by estimation of F(ST) index (values ranging from 0.75% to 6.00%) for various breed combinations. The neighbour-joining tree constructed from chord distances, multidimensional scaling (MDS) display of F(ST) values and Bayesian clustering approach consistently identified the Toda, Jaffarabadi, and Pandharpuri breeds as one lineage each, and the Bhadawari, Nagpuri, Surati, Mehsana and Murrah breeds as admixture. Analysis of molecular variance refuted the earlier classification of these breeds proposed on the basis of morphological and geographical parameters. The Toda buffaloes, reared by a tribe of the same name, represent an endangered breed from the Nilgiri hills in South India. Divergence time of the Toda buffaloes from the other main breeds, calculated from Nei's standard genetic distances based on genotyping data on seven breeds and 20 microsatellite loci, suggested separation of this breed approximately 1800-2700 years ago. The results of the present study will be useful for development of rational breeding and conservation strategies for Indian buffaloes.

Animals↗

PubMed1999

Endocrine correlates of parental care in an Antarctic winter breeding seabird, the emperor penguin, Aptenodytes forsteri.

Plasma levels of luteinizing hormone (LH) and prolactin associated with parental behavior were measured in the Antarctic winter breeding emperor penguin, Aptenodytes forsteri. Males exclusively incubate the egg while females exclusively brood the nonhomeothermic young; both sexes alternate in rearing the homeothermic young. Birds were sampled on arrival from the sea through egg laying, incubation, and brooding. All parent birds lost their chicks at the end of the brooding period due to harsh weather but sampling continued. In females, LH titers dropped after egg laying but levels were restored when the birds returned from the sea to brood the chicks and were not depressed by high prolactin levels. Plasma prolactin remained low in males captured on arrival and kept until the free-living males finished incubation. In breeders, prolactin secretion increased during the prelaying period when day length decreased. Prolactin levels stayed elevated in males during incubation and in brooding females returning after a 2-month absence at sea. Prolactin values were higher in brooding females than in males ending incubation or returning in late brooding. These levels did not drop after chick loss, and the sexual difference in prolactin values was maintained after breeding failure. In emperor penguins, increased prolactin secretion appears to be triggered around the time of egg laying and continues, driven by an endogenous mechanism, through incubation and brooding until rearing is completed. Prolactin secretion independent of external stimuli may have evolved in pelagic seabirds to maintain parental care despite long absences at sea from the breeding colony.

Animals↗

PubMed1980

Blood groups : immunogenetic markers in primate animals and their use in breeding and standardization.

The importance of immunogenetics for definition and standardization of laboratory animals has been demonstrated by their successful application for breeding of laboratory mice and rats, and in planned breeding of large domestic animals. Among the immunogenetic markers used, blood groups are the best known and generally considered as the most important. For close to two decades, serology and genetics of blood groups have been investigated by this Laboratory in the most commonly used laboratory primates, namely, macaques, (rhesus, crab-eating, pig-tailed and bonnet), baboon (olive, yellow and hamadryas) as well as chimpanzees. Blood groups of many other primate species have also been surveyed but in a less intensive manner. Blood groups of apes and monkeys are defined by standard methods of human serohematology, using both reagents developed for typing human blood and reagents obtained from the sera of immunized primate animals. The presently available reagents define, depending on species, between 10 and 25 blood groups in macaques, 20 to 25 blood groups in baboons and 45 types in chimpanzees. The available blood group genetic markers will be listed and their value for standardization and breeding of laboratory primates will be discussed.

Animals↗

PubMed1975

[ Glucose concentration in blood during exertion. 5. Use of the total distribution of blood glucose values during physical exercise or the estimation of response to exertion in various breeds of swine].

Blood glucose was determined by an enzymic method in 56 pigs of the German Edelschwein, German Landrace, German Saddleback breeds and Edelschwein/Landrace crosses before, during and after exercise on a belt moving at 1.3 metres/second for ten minutes, at 10 degrees C (winter) or 22-34 degrees C (summer) and relative humidity of 65-75%. Total plasma glucose was calculated from the plasma volume. Total scatter of values for blood glucose concentration and total plasma glucose was greater in Edelschwein and Saddlebacks than in Landrace and the crossbred pigs. There was a close and significant relationship between individual regulatory capacity and breed. The total scatter of blood glucose values was greater in winter than in summer.

Animals↗

PubMed2006

Genetic characterization of Argentine and Bolivian Creole cattle breeds assessed through microsatellites.

In the present report, the polymorphisms from 9 microsatellites were used to assess genetic diversity and relationships in 4 Creole cattle breeds from Argentina and Bolivia, 4 European taurine breeds, and 2 American zebu populations. The Creole populations display a relatively high level of genetic variation as estimated by allelic diversity and heterozygosity, whereas the British breeds displayed reduced levels of genetic diversity. The analysis of molecular variance indicated that 7.8% of variance can be explained by differences among taurine and zebu breeds. Consistent with these results, the first principal component (PC), which comprised the 40% of the total variance, clearly distinguishes these 2 groups. In addition, all constructed phylogenetic trees cluster together Nelore and Brahman breeds with robust bootstrap values. Only 1% of variance was due to difference between American Creole and European taurine cattle. Although this secondary split was supported by the classical genetic distance and the second PC (15%), the topology of trees is not particularly robust. The presence of zebu-specific alleles in Creole cattle allowed estimating a moderate degree of zebu admixture. When these data were compared with mitochondrial and Y chromosomal studies, a clear pattern of male-mediated introgression was revealed. The results presented here contribute to the understanding of origin and history of the American Creole cattle.

Alleles↗

PubMed1995

Breed differences in the plasma renin activity and plasma aldosterone concentration of dogs.

Plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were studied in 90 clinically healthy dogs: 15 Beagles, 15 Cavalier King Charles spaniels (CKCS), 15 Medium Sized Poodles, 15 Labrador retrievers, 15 Irish wolfhounds and 15 Newfoundlands. All dogs were fed a low sodium diet for at least 3 days before blood sampling in a home setting. There was a significant difference between breeds with respect to both PRA (P = 0.0002), PAC (P = 0.002) and PRA/PAC ratio (P < 0.0001). The highest PRA values were found in CKCS and Poodles, two breeds known to be predisposed to chronic valvular disease. Five CKCS had PRA values exceeding 3.0 ng/ml/h while this was the case in only one of the remaining 75 dogs. In contrast to the high PRA values, CKCS had low PAC values, and therefore much higher PRA/PAC ratios than the other breeds. In Irish wolfhounds, both the PRA and PAC values were low. In conclusion, considerable breed differences in PRA and PAC were found in the present study. Further studies are needed to determine if there is an association between developing chronic valvular disease and a high PRA in dogs.

Aldosterone↗

PubMed1999

Studies on the energy content of pigeon feeds II. Determination of the incorporated energy.

The effect of breed and sex on adult body composition of four pigeon breeds: Texan (TEX), Mondain (MON), Szeged Tumbler (SZT), and homing (HOM) and on the digestibility coefficients (DC) and metabolizable energy (ME) content of their feeds was studied. A total of eight groups, each comprising five males and five females of each breed, were used. All birds were fed the same pelleted pigeon feed (17.27% CP) ad libitum. After the metabolic study, the whole body was analyzed for dry matter (DM), ash, CP, and ether extract (EE) contents. The DC of DM, TEX, MON, and HOM pigeons did not differ significantly, whereas DC for the SZT breed were consistently lower. In the majority of cases, the DC values obtained for males were higher, irrespective of the breed. The body composition of the two sexes was first compared within a given breed, and no major differences were detected. Interbreed differences were greater. The DM content of the body of HOM pigeons exceeded that of the other three breeds for both sexes. For ash and CP content of the body, the reverse was found, i.e., the values of both parameters were lower in HOM pigeons. The HOM pigeons had significantly (P < 0.05) higher body fat (EE) content as compared with the other three breeds except TEX females. The NFE value for HOM also tend to be higher than in the other three breeds.

Adipose Tissue↗

PubMed1976

The hydro-chemical and physical conditions of the environment of the immature stages of some species of the simulium (Edwardsellum) damnosum complex (Diptera).

Water samples were collected from breeding sites of species of the Simulium (Edwardsellum) damnoslm complex in Upper Volta, Liberia and Cameroon during the dry season; and in Tanzania and Kenya at various seasons during a period of two years. The following 20 factors were analysed at 45 breeding sites: water temperature, current velocity, pH value, conductivity free carbon dioxide, oxygen content, calcium, magnesium, potassium, sodium, alkalinity, chloride, sulphate, nitrite, nitrate, ammonium, phosphate, silicate, total iron and organic substance (consumption of potassium permanganate). A number of notable differences in the chemical composition of the water of the breeding sites of 13 S. damnosum complex species were found, particularly with regard to the pH and conductivity. On the basis of these differences the various species can be divided into three main groups: Group I: 3 species (S. sanctipauli, S. yahense, "Menge"); breeding in sites with pH values always below 7 and conductivity values below 50 mumhos. Group II: 8 species (S. sirbanum, S. sudanense, S. damnosum s.s., S. squamosum, "Sanje", "Nkusi", "Nyamagasani", "Jovi"); breeding in watercourses with neutral, weakly acid or weakly alkaline reactions and conductivity values ranging from 50 to 150 mumhos. Group III: 2 species ("Kibwezi", "Kisiwani"); breeding in watercourses characterized by highly alkaline reactions with pH values between 7.7 and 10 and by conductivity values between 400 and 950 mumhos. The vectors of Onchocerca volvulus are included in group I and II only.

Animals↗

PubMed2001

Inter-breed differences in equine forelimb kinematics at the walk.

Linear, temporal and angular biokinematic characteristics of the forelimb at the walk in different breeds were determined, highlighting inter-breed differences. Twenty-three healthy stallions were used: ten Andalusians (AN), seven Arabs (AR) and six Anglo-Arabs (AA). Height at the withers was significantly different between groups (P < 0.001). Six trials per horse were recorded using a levelled video camera (sampling frame rate 25 frames/s), digitized and analysed using a semi-automatic movement analysis system. No statistically significant differences in speeds were recorded between breeds (P > 0.05). The only temporal parameter which was similar in the three breeds was the moment at which the hoof reached the highest point in its trajectory. The variables presenting the most significant differences were the percentages of deceleration and propulsion within the stance phase. ANOVA for angular variables showed that the greatest difference was in the range of angular movement of the carpal joint, being higher in AN, due to a lower minimum value. In the fetlock joint, the greatest difference was observed in minimum values, which differed in all three breeds. Significant inter-breed differences were also observed for maximum limb retraction, being lowest in the AN group, followed by the AA and AR groups. This finding was reflected in the angular range of motion, despite smaller differences in the degree of limb protraction; very similar values were reported in all three breeds. As regards the elbow joint, no inter-breed differences were observed in terms of minimum values, whereas differences were recorded for maximum and angular range of motion, higher values being displayed by the AR and AN groups than by AA animals. In conclusion, inter-breed differences may be determined in equine forelimb biokinematics at the walk. This study distinguished between AN, AR and AA horses.

Animals↗

PubMed1975

Annual cycle of plasma luteinizing hormone concentrations in wild mallard drakes.

Plasma LH concentrations were followed in 9 individually marked wild mallard drakes in Kiel (54 degrees N) for one year at monthly intervals. Mean LH levels increased during the spring and reached the annual maximum in April and May. In June when testicular regressions occurs, the LH titer sharply decreased and was lower than at any other phase of the annual cycle. In late fall mean plasma LH concentrations increased and, whilst not reaching the values observed during the breeding season, remained relatively high during the winter. Thus, in the mallard LH can be released under short and long daily photo-periods.

Animals↗

PubMed2026

Dissecting genetic architecture and improving machine learning‑based genomic prediction of flowering time in Osmanthus fragrans by integrating structural variants.

Sweet osmanthus (Osmanthus fragrans), a traditional ornamental plant in China, exhibits substantial variation in autumn flowering time, which significantly affects landscape application and cultivation efficiency. Here, we performed a genome-wide association study on 127 resequenced accessions classified into early, intermediate, and late flowering types, using a set of 2,325,410 single-nucleotide polymorphisms (SNPs) and 246,824 structural variants (SVs). By integrating SNP/insertion and deletion (Indel) and SV data with weighted gene co-expression network analysis, machine learning, and genomic prediction, we dissected the genetic architecture of flowering time. We identified 24 associated SNP/Indels and six SVs, mapping to 30 candidate genes, including known flowering regulators FLK, LOS1, Y14, MIF2, and GID1B. These genes showed tissue-specific expression, with some responding to low temperature. The two hub genes, GUX1 and LYG027904, were located within modules of the co-expression network associated with low-temperature treatment. Haplotype analysis revealed a specific three-SNP haplotype associated with late flowering and linked to LOS1, and epistatic interactions among combined genotypes contributed to phenotypic variation. Notably, integrating SVs with SNP/Indels improved genomic prediction accuracy; the gradient boosting decision tree model outperformed other machine learning algorithms, achieving a mean accuracy of 0.859 and an AUC > 0.8 (where AUC is area under receiver operating characteristic curve) for all flowering types. These findings provide insights into the genetic mechanisms underlying flowering time variation in O. fragrans, offer candidate genes and haplotypes for molecular breeding, and highlight the value of integrating SVs with machine learning for genomic prediction in woody ornamentals.

Machine Learning↗

PubMed1994

Comparison of the semen characteristics of Fengjing, Meishan and Yorkshire boars.

Semen characteristics of Chinese Fengjing, CHinese Meishan and American Yorkshire boars were examined. Samples were collected from 24 boars: 6 Fengjing, 12 Meishan and 6 Yorkshire. Three semen characteristics and 6 biochemical evaluations of semen or seminal plasma were analyzed. The whole semen parameters measured were gelatinous (gel) and gel-free volume and progressive motility. Fengjing boars were higher in gel volume than Meishan (P < 0.05) but not Yorkshire boars (P > 0.25), while Yorkshire boars were higher than Meishan boars in gel volume (P < 0.10). The gel-free volume was higher in Yorkshire and Fengjing boars than Meishan boars (P < 0.10), but Fengjing gel-free volumes did not differ from Yorkshire gel-free volumes (P > 0.80). However, the only difference detected for progressive motility was between Fengjing and Meishan boars (78.5 vs 74.5%; P < 0.10). Sperm concentration was higher in Meishan than Yorkshire boars (P < 0.01) although these breeds did not differ from Fengjing boars (P > 0.18). The biochemical messurements made were fructose, galactose, inositol, total carbohydrate and total protein in seminal plasma and pH in gel-free semen. Fengjing boars had higher concentrations of galactose in seminal plasma than Meishan or Yorkshire boars (P < 0.05), while Meishan seminal plasma had higher galactose concentrations than Yorkshire seminal plasma (P < 0.10). Fructose, inositol and total carbohydrate concentrations were all higher in Fengjing and Meishan seminal plasma than Yorkshire seminal plasma (P < 0.05). Fengjing seminal plasma had higher levels of inositol than Meishan seminal plasma (769 vs 566 mg/100 ml; P < 0.10). Furthermore, Fengjing and Meishan semen had similar fructose and total carbohydrate concentrations (P > 0.80). The pH level and total protein concentration did not differ among the 3 breeds (P > 0.30). This study indicated that breed differences were detected for several seminal parameters, although no single breed had consistantly higher values for all the parameters measured.

Journal Article↗

PubMed1990

Platelet serotonin level in rats is under genetic control.

It has recently been shown that platelet serotonin (5-hydroxytryptamine, 5HT) levels (PSL) in Wistar rats represent an individually stable biological parameter (neither subject to periodic oscillations nor markedly influenced by sex and age) that shows a unimodal frequency distribution within the population (range: 1.2-2.2 micrograms 5HT/mg platelet protein). To investigate the genetic background of PSL, selective breeding for the extreme values of this trait was performed. In the fourth generation, two discrete sublines of animals (statistically different from the unselected population) with constitutionally high or low PSL could be discerned: one with congenitally low PSL (1.1-1.6 micrograms 5HT/mg platelet protein; approximately normal distribution) and the other with congenitally high PSL (1.6-2.9 micrograms 5HT/mg platelet protein; irregular distribution). No difference in the pattern of inheritance between sexes could be discerned. The results demonstrated a marked heritable component underlying the expression of individual values of PSL in rats, suggesting that this parameter is a trait characteristic.

Animals↗

PubMed2026

The domestication-associated WHP10 tandem cluster of amino acid transporter genes enhances whole-plant protein accumulation in maize.

Improving protein accumulation in maize is essential for sustainable agriculture, yet the regulatory mechanisms governing the intermediate "flow" of organic nitrogen remain elusive. Here, we show that the maize stem acts as a regulatory node for nitrogen allocation. By integrating spatial transcriptomics and metabolomics with quantitative genetics, we demonstrate that a transport-oriented stem program orchestrates the high-protein phenotype of the wild maize accession Ames21814. We identified a major locus, Whole-plant High Protein 10 (WHP10), that encodes a tandemly duplicated cluster of amino acid transporter genes. WHP10 exhibits strong vascular-biased expression, driven by promoter divergence that enhances the wild allele's activity. Functional assays and genetic validation support a model in which the WHP10 cluster facilitates the transport of multiple nitrogen-rich amino acids, thereby contributing to vascular-associated amino acid transport and post-uptake organic-nitrogen partitioning. Our findings establish stem flow as a regulatory layer for protein accumulation and identify WHP10 as a high-value target for precision breeding to enhance whole-plant protein accumulation without compromising grain yield.

Zea mays↗