Oral administration of Kaempferia parviflora did not disturb male reproduction in rats

To investigate the androgenic effect of Kaempferia parviflora (KP), a Thai herbal plant, adult male rats were randomized into control and KP-treatment groups. Rats were treated orally with water in the control group and with 1,000 mg/kg/day of KP in the treatment group for 45 days. Blood samples were collected on days 10, 20, 30 and 45 for measurement of the serum follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone, progesterone and corticosterone levels. The reproductive and non-reproductive organs were dissected on day 45 and weighed. Mating behavior was also observed on days 20 and 30. Body weight was measured throughout the study period. The results showed that KP induced an increase in body weight compared with the controls. There were no significant differences in the weights of either reproductive (testis, seminal vesicle plus coagulating gland, levator ani muscle plus bulbocarvernosus muscle and glans penis, except the prostate gland) or non-reproductive organs (kidney, adrenal gland and gastracnemius muscle). There were no significant differences in serum levels of either FSH or LH between the two groups. The serum testosterone and progesterone levels were insignificantly lower in the KP group during the first 30 days. The serum corticosterone levels in the KP group were lower than those in the controls throughout the study period and were significantly low on days 20 and 30. There were no significant changes in mating behavior in the rats treated with KP. Although KP affected the body weight and serum corticosterone level, it did not affect mating behavior, reproductive and non-reproductive organ weights or hormones related to the reproductive system in the adult male rats. Therefore, we conclude that the testosterone-like effect of KP did not disturb the hypothalamic-pituitary-testicular axis or male reproduction.     

Selected Aspects of Advanced Porcine Reproductive Technology

In vitro fertilization (IVF) of in vitro matured (IVM) oocytes in pigs has become the most popular method of studying gametogenesis and embryogenesis in this species. Furthermore, because of recent advances in in vitro culture (IVC) of IVM–IVF embryos, in vitro production (IVP) of embryos now enables us to generate viable embryos as successfully as for in vivo -derived embryos and with less cost and in less time. These technologies contribute not only to developments in reproductive physiology and agriculture but also to the conservation of porcine genetic resources and the production of cloned or genetically modified pigs. However, in IVP, there still remains the problem of abnormal ploidy, which is caused by performing procedures under non-physiological conditions. In recent years, unique technologies such as intracytoplasmic sperm injection (ICSI) or xenografting of gonadal tissue into immunodeficient experimental animals have been developed to help conserve gamete resources. These technologies combined with IVP are expected to be useful for the conservation of gametes from important genetic resources. Here, we discuss the developmental ability and normality of porcine IVP embryos and also the utilization of ICSI and xenografting in advancing biotechnology in pigs.     

Sequence of the domestic duck (Anas platyrhynchos) growth hormone-encoding gene and genetic variation in the promoter region

The duck growth hormone encoding gene and its promoter region were amplified by polymerase chain reaction (PCR). A total of 5.25 kb were cloned and sequenced. Duck growth hormone (GH) consists of five exons and four introns and is structurally similar to mammalian and chicken GH gene. Although the distal region of duck GH promoter showed no similarity to chicken and turkey promoters, the proximal region of the promoter contained two putative Pit‐1 binding sequences, and showed similarity to chicken and turkey GH promoters. Genetic variation was detected at five positions of the promoter region. The results of this study indicate that the expression of duck GH is likely regulated in a similar manner to that of chicken GH via enhancer‐type cis‐acting elements and the presence of genetic variation in the duck GH gene may be applicable to marker‐assisted selection.     

30个紫花苜蓿品种对苜蓿花叶病毒病的田间抗性初步研究

为了比较不同紫花苜蓿品种对病毒病的抗性,对30个紫花苜蓿品种的病毒病发病情况进行了田间调查,利用小RNA深度测序技术结合RT-PCR技术检测鉴定各紫花苜蓿品种中的病毒种类,并测定了各紫花苜蓿品种的发病率、病情指数、相对株高、相对单株干重、相对茎秆直径、相对叶面积、相对叶长和相对叶宽,综合比较各紫花苜蓿品种的抗性,并对部分指标进行系统聚类分析。结果表明:30个紫花苜蓿品种均只受到苜蓿花叶病毒(alfalfa mosaic virus, AMV)的侵染,所有紫花苜蓿品种的田间发病率均超过94%,病情指数范围为31.53～55.50;30个紫花苜蓿品种中,抗性较强的品种有1个,为射手2号,抗性一般的品种有6个,其余23个品种的抗性较差,分别占供试品种的3.33%,20.00%和76.67%;聚类分析结果表明,抗性较强的射手2号与其他紫花苜蓿品种的亲缘关系较远,与其杂交有可能产生较大的杂种优势。     

Sucrose assists selection of high‐quality oocytes in pigs

We investigated whether high‐quality in vitro matured (IVM) oocytes can be distinguished from poor ones based on the morphological changes after treatment with hyperosmotic medium containing 0.2 mol/L sucrose in pigs. We hypothesize that IVM oocytes maintaining round shape have higher quality than mis‐shapened oocytes following dehydration. Oocyte quality was verified by determining embryonic developmental competence using in vitro fertilization, nuclear transfer and parthenogenetic activation. In all cases, the round oocytes had greater (p < .05) developmental competence than that of mis‐shapened oocytes in terms of blastocyst rate and total cell number in blastocysts obtained after 6 days of in vitro culture. We also confirm that round aged oocytes are higher in quality than mis‐shapened aged oocytes. In an attempt to find out why high‐quality oocytes maintain a round shape whereas poorer oocytes become mis‐shapened following sucrose treatment, we examined the arrangement of actin microfilaments and microtubules. Abnormal organization of these cytoskeletal components was higher (p < .05) in mis‐shapened oocytes compared to round oocytes after 52 hr of IVM. In conclusion, sucrose treatment helps selection of high‐quality oocytes, including aged oocytes, in pigs. Abnormal cytoskeleton arrangements partly explain for low developmental competence of mis‐shapened oocytes.     

Simultaneous evaluation of spatial working memory and motivation by the allocentric place discrimination task in the water maze in rats.

In order to evaluate learning and memory deficits separately from and simultaneously with motivational, motor and sensory impairments in identical animals, we developed the allocentric place discrimination task test using a water maze in rats. For this assessment task, two similar, visible platforms, one was fixed and the other was floating, were simultaneously present in a pool, and the working memory of the allocentric place discrimination task was evaluated. After training, the task accuracy was high about 85% correct and animals were used repeatedly. The accuracy decreased significantly when the pool was surrounded with a black curtain. Muscarinic receptor antagonist scopolamine 0.5 mg/kg selectively impaired the accuracy. Muscle relaxant dantrolene 10 mg/kg selectively decreased swimming speed. Under low motivational condition (warm water), still time increased and swimming speed decreased, but the accuracy was not affected. Similar to warm water, opioid receptor agonist morphine 15 mg/kg increased still time and decreased swimming speed. These results suggest that the allocentric place discrimination task is useful in evaluating spatial working memory ability independently of and concurrently with also visual, motor ability and motivation in identical animals.     

Prevalence and persistence of Salmonella in broiler chicken flocks.

Cecal contents of 2,345 broiler chickens consisting of 28 flocks originated from 12 farms were examined for the prevalence of Salmonella to know the actual status of infection with Salmonella in the chicken flocks. Salmonella was isolated from 336 (14.3%) samples. From these isolates, eight serovars were identified. Of the 336 Salmonella isolates, 242 (72.0%) were serotyped as S. Blockley, 60 (17.9%) S. Hadar, 15 (4.5%) S. Bredeney, nine (2.7%) S. Schwarzengrund, four (1.2%) S. Anatum, three (0.9%) S. Enteritidis, two (0.6%) S. Ohio, and one (0.3%) S. Livingstone. The same serovars of Salmonella were repeatedly found in the chickens from the same farms. S. Typhimurium and S. Enteritidis were detected in pooled broken eggshell samples collected from the hatchery. Analysis of plasmid profiles revealed 11 patterns of S. Blockley and seven patterns of S. Hadar. Strains of the same plasmid profiles of S. Blockley were isolated repeatedly from the same farm over one year after the first isolation.     

高粱—苏丹草杂交种的应用可行性研究及其选育

利用生产上推广的６个粒用高粱杂交种和４个高粱杂交种为对照,与随机组配的１５个高粱－苏丹草杂交种进行比较。结果表明,高粱－苏丹草杂交种做饲用生产能力上仅次于甜高粱杂交种,但在早熟优质等若干特性上优于甜高粱,有些组合还高于甜高粱杂交种的生产能力。该类型杂交种干物质及绿色体的日生产能力高于甜杂２号２１．１％和４１．２％,原因是杂最高。     

Comparison of morphological and DNA-based techniques for stomach content analyses in juvenile chum salmon <Emphasis Type="Italic">Oncorhynchus keta</Emphasis>: a case study on diet richness of juvenile fishes

To identify the stomach contents of marine organisms, morphological observations are commonly conducted. However, the results obtained by this traditional method are frequently biased, as it is difficult to detect partially digested, soft-bodied organisms. To resolve this, recent studies have used DNA-based (DNA barcoding) analyses to examine the diet breadth of marine organisms. Here, we compared the prey richness of juvenile fishes using morphological observations and DNA-based analyses, with a focus on juvenile chum salmon Oncorhynchus keta. A higher number of prey taxa were successfully identified using DNA-based analyses than morphological observations. However, we also noticed several shortcomings of the DNA-based analyses, as reported in other diet-analysis studies that used molecular techniques. For example, the degree of digestion among prey taxa might have resulted in differential sensitivity to DNA detection. Additionally, several prey taxa could not be precisely identified, as the sequence data for some of the targeted organismal groups are unavailable in public gene databases. Remarkably, it is also possible that DNA-based analyses detected secondary prey, and therefore, the richness of prey taxa was likely overestimated. Thus, dietary analyses of juvenile fishes need to be carefully conducted, considering the respective advantages and disadvantages of DNA-based and morphological techniques.