Differences in Root and Shoot Response to Limited N-supply in Oat and Spring Barley

Oat and spring barley cultivars, varying in origin and date of release, were examined in soil boxes with sloped glass-face. Considerable genotypic differences were found in shoot and root response to high and low nitrogen supply. Oat cultivars, representing a wider germplasm collection, exhibited a stronger and partially different shoot and root response to applied N-levels than barley cultivars. Cultivar-fertilization interaction effects were significant for seminal and adventitious root variation. Genotypic specificity (plasticity) in root response, as revealed in some oat and barley cultivars with a deeper penetration and more vigorous root growth under the low N-supply, was recognized to be a valuable adaptive characteristic for breeding plants on light-textured soils.     

Freezability and Fertility Results with Uncentrifuged Stallion Semen

The first (1 to 3) sperm-rich fractions of the ejaculate were collected from 4 stallions using an open-ended vagina. The volume of the collected fractions was 12 ± 8 ml with a density of 475 ± 200 million spermatozoa/ml. Before freezing, the semen was diluted with a skim-milk based extender 1:1 to 1: 8 (volume of semen: volume of extender), depending on the initial sperm concentration to achieve a final concentration of 100 million/ml. The total number of spermatozoa in an insemination dose ranged from 0.7 to 1 billion spermatozoa. Within 12 h after ovulation, 48 mares were inseminated in 70 cycles. The total single-cycle pregnancy rate at day 21 was 24%, but varied from 10% to 33% per cycle among the stallions.     

Advancement of Ovulation in the Sow Related to Seminal Plasma Application before Insemination

Contents: The relationship between seminal plasma constitutents in the boar ejaculate and ovulation time was investigated in German landrace gilts in a total of 182 heat periods. The animals were inseminated in the first two trials (I = 34 gilts; II = 60 gilts) once at spontaneous heat with seminal plasma free liquid semen after a pretreatment with either 60 ml seminal plasma or dilution medium. In a third experiment (III) 22 gilts were treated in 4 subsequent heat intervals with 120 ml seminal plasma, oestrogen solution or physiological saline at the beginning of standing heat without any application of spermatozoa to investigate the possibility of induction of ovulation. In the inseminated gilts embryos were recovered surgically 3 to 5 days after AI. Fertilization rate and embryo quality were recorded. The time of ovum activation was calculated in a retrospective manner using the corresponding age values of Hunter (1974) for embryo development. Considering a six hour lapse after ovulation for complete activation of all eggs, the probable ovulation time was determined and used for calculation of the interval between insemination and ovulation. In two experimental groups ovulation was determined by trans cutaneous sonography of the ovaries in the standing gilt. This method revealed a seminal plasma dependent advancement of ovulation time ranging between 5 and 14.4 hours. A seminal plasma dependent prostaglandin release in the endometrium is believed to be the main factor in stimulation of the ovulation process .     

蜜蜂父系研究进展

Hamilton把人工授精技术运用于昆虫之后,昆虫的遗传特性和社会结构就成为了生物进化研究中的核心内容之一.如果能确定特定蜂群内工蜂之间的血缘关系,就能够更好地理解和解释群体行为和个体行为的产生机制,以及社会性昆虫的进化特点.主要介绍国内外有关蜜蜂父系研究的最新进展.     

Variations in the Length of the Y Chromosome and the Seminal Attributes of Karan Fries Bulls

Fresh semen and blood samples from 20 Karan Fries bulls (4–6 years of age), maintained at the Artificial Breeding Complex of the National Dairy Research Institute, Karnal, were collected for one year. All the bulls had 60 chromosomes, comprising 58 acrocentric autosomes and 2 sex chromosomes, with X as the larger and Y as the smaller submetacentric. The mean lengths of Y_p and Y_q; the total length of the Y chromosome and the length ratio were 1.10±0.01 m, 1.83±0.02 m, 2.92±0.02 m and 62.46%±0.18%, respectively. Analysis of the length measurements of the the Y chromosomes in Karan Fries bulls showed that all the measurements, viz., the short arm of the Y chromosome, the long arm of the Y chromosome, the total length of the Y chromosome and the variation in length of Y chromosome, varied significantly among bulls. All the seminal parameters, the volume of semen, mass activity, initial motility, concentration, live sperm count and the total abnormal sperm count, were significantly affected by bulls, whereas season had a significant effect on all the seminal parameters except the total abnormal sperm count. No significant relationship between the ratio of the long arm to the total length of the Y chromosome and seminal attributes was observed.     

Retracted: Effects of multiple collections on spermatozoa quality of Persian sturgeon,Acipenser persicus: motility,density and seminal plasma composition

In this study, we investigated the effects of multiple collections of sperm on the endangered Persian sturgeon, Acipenser persicus, in terms of a number of sperm functional parameters (percentage of motile spermatozoa, total time period of motility and sperm concentration) as well as on the ionic composition, protein concentration and osmolality of seminal plasma. Semen samples were collected from 12 induced male fish in three experimental groups that had been injected intramuscularly with LHRH‐A₂, at dosages of 5 μg/kg body weight, at a number of time regimes: at 12 h, 17 h and 24 h after spawning induction (1); at 24, 29 and 34 h after spawning induction (2); and at 36, 41 and 46 h after spawning induction (3). The percentage of motile spermatozoa and the period of sperm motility decreased significantly (p < 0.05) after the second and third collections. The concentration of spermatozoa decreased after the third collection, but this decline was not significant. No significant effect of multiple collections on protein concentration and ionic content (with exception of the Cl^? ion) of seminal plasma was observed. In all experimental groups, a moderate impact of sequential collection on the osmolality (p < 0.05) of seminal plasma was observed. This study provides new data on the effects of multiple collections on spermatological characteristics in the Persian sturgeon. Our results confirm that sequential stripping after the third collections has a negative effect on a number of functional parameters associated with sperm.     

Carcinoma of an accessory genital gland in a 23‐year‐old Camargue gelding

This report describes the case management, histopathological and post mortem findings in a 23‐year‐old gelding with a peri‐rectal mass. The mass was debulked surgically and submitted samples revealed it to be a poorly differentiated carcinoma. In the post operative period the horse developed signs of abdominal pain and dysuria and was subjected to euthanasia. Post mortem examination revealed a large infiltrative mass located between the rectum and urethra, consistent with a carcinoma of an accessory genital gland, most likely the seminal vesicle.     

Influence of seminal plasma during different stages of bovine sperm cryopreservation

This study aimed to evaluate the effect of seminal plasma on bovine sperm cryopreservation and to assess the integrity of plasma and acrosomal membranes, mitochondrial potential, remodelling of F-actin cytoskeleton and sperm chromatin fragmentation during the cooling, equilibrium and freezing/thawing stages. Six ejaculates collected from seven Nelore bulls (n = 42) were used in this study. Each ejaculate was divided into two aliquots (with seminal plasma = SP group; without seminal plasma = NSP group) and packed to a final concentration of 50 × 10⁶ sperm per straw. Statistical analyses were performed using SAS software (version 9.3), and p ≤ .05 was considered significant. A time effect was observed for all sperm characteristics (p < .05), except for chromatin fragmentation (p > .05). The presence of seminal plasma better preserved the acrosomal integrity (SP = 75.2% and NSP = 71.7%; p < .05) and also provided lower F-actin remodelling during cryopreservation process (SP = 29.9% and NSP = 32.4%; p < .05). Regarding to the cryopreservation stages, it was observed that cooling step induced higher remodelling of F-actin than the equilibrium and freezing/thawing stages (56.3%, 32.2% and 23.9%, respectively; p < .05). The equilibrium step had minor influence on overall sperm characteristics while the freezing/thawing stage was responsible for the highest percentage of damage in plasma membrane (−65.2%), acrosomal membrane (−34.0%) and mitochondrial potential (−48.1%). On the other hand, none of the cryopreservation stages affected chromatin integrity. It was concluded that the presence of seminal plasma provides increased acrosomal integrity and reduced remodelling of F-actin cytoskeleton. Higher F-actin remodelling is observed after the cooling step while the freezing/thawing step is most damaging to sperm membranes and mitochondrial potential during bovine sperm cryopreservation.     

玉米植株叶片和根系的抗旱性差异分析

为了研究玉米(Zea mays L.)的叶片和根系抗旱性差异,以田间种植的玉米品种‘掖单13’和‘丹玉13’为材料,在拔节期取样,分别对玉米的叶片、叶鞘及初生根、第1层至第5层次生根的基部、中部和根尖的保水能力进行了研究。结果显示,拔节期玉米不同器官保水能力不同,叶鞘的保水能力最强,其次是根系,叶片的保水能力最弱。初生根和各层次生根不同部位相比较,根基部保水能力最强,其次是根中部,根尖的保水能力最弱;不同类型根保水能力相比较,初生根基部、中部和根尖部分的保水能力均最弱;第1层至第5层次生根基部的保水能力是根系发生时间越晚,其保水能力越强;根中部和根尖的保水能力在第1层至第5层次生根中有不同表现。