排序方式: 共有23条查询结果,搜索用时 640 毫秒
1.
Darnel ( Lolium temulentum ), a weed of wheat and barley, is either awned or awnless. The role of the darnel awn in dispersal was investigated in relation to human's agricultural practices in cereal cultivation in a Malo village, Gaytsa, south-western Ethiopia. In 24 free-threshing wheat fields and 11 emmer wheat fields, 129 and 88 spikes (one spike per plant), respectively, of darnel were randomly sampled. At the market in Gaytsa, 11 free-threshing wheat grain samples and eight emmer wheat grain samples of 150–200 g were collected. For each grain sample, the number of wheat grains and awned and awnless grains of darnel were recorded. The relative percentage of the awned form in free-threshing wheat fields was 8.53% and that in emmer wheat fields was 70.45%. The relative percentage of awned grains in free-threshing wheat grains from the market collection was 3.55% and that in emmer wheat grain lots was 75.20%. The morphology of awned darnel grains resembles emmer wheat grains and awnless darnel grains resemble free-threshing wheat grains. Thus, grain mimicry controls the close association of the two forms of darnel with the wheat species. The lack of an awn itself functions for darnel grain as a dispersal mechanism in free-threshing wheat cultivation systems compared with other wild grass species. 相似文献
2.
Horiguchi K Naito J Ishida M Harigaya T 《The Journal of reproduction and development》2007,53(3):515-523
Several studies have indicated that prolactin (PRL) assumes oligomeric, proteolytically cleaved, phosphorylated and glycosylated forms. Phosphorylated PRL (PPRL) is considered to be the most important posttranslationally modified form in the rat. In the present study, we examined whether or not PRL is present in the mouse pituitary gland in the phosphorylated form. Mouse pituitary PRL was digested with acid phosphatase, resolved by two-dimensional gel electrophoresis, stained with Coomassie brilliant blue, and then immunoblotted against the anti-PRL, anti-phosphoserine and anti-phosphothreonine antibodies. We also examined whether PRL is phosphorylated by protein kinases and semi-quantified the ratios of PPRL to PRL in the pituitary gland. The results indicated that three types of PRL are present in the pituitary glands of both male and female mice. One was non-phosphorylated (isoform 1), and the other two were immunoreactive to anti-phosphoserine (isoform 2) and/or anti-phosphothreonine (isoform 3) antibodies. The ratio between isoforms 2 and 1 of the 30-day-old female mice was higher than that of the 20-day-old female mice. However, the ratios among the three isoforms in the male pituitary glands did not differ with age. The ratio of PPRL to isoform 1 was obviously reduced after ovariectomy (OVX), and it recovered with estrogen replacement. These results suggest that estrogen influences PRL phosphorylation in female mice. 相似文献
3.
Katsuhiro OHKOSHI Seiya TAKAHASHI Shin-ichiro KOYAMA Satoshi AKAGI Noritaka ADACHI Tadashi FURUSAWA Jun-ichiro FUJIMOTO Yoshiaki IZAIKE Tomoyuki TOKUNAGA 《Animal Science Journal》2003,74(4):269-276
In vivo matured oocytes collected by laparoscopic follicular aspiration (LFA) from hormone treated female goats were used as recipient ooplasts for somatic cell nuclear transfer (SCNT). Japanese native (Shiba) goats were used as donor females and some donor females were used repeatedly (two or three times) at intervals of a few months. To induce synchronization of estrus, a sponge containing 0.5 g of progesterone was inserted into the vagina of each goat for 14 days. These animals were also treated with follicle stimulating hormone (FSH) in a series of 8 injections over 4 days. The first FSH injection was administered on the morning of day 9 of sponge insertion. On the morning of day 13, 50 µg of gonadotropin‐releasing hormone (GnRH) was injected into each animal. Twenty‐nine hours after GnRH injection, LFA was performed. After removal of cumulus cells, collected oocytes with the first polar body were selected and enucleated for nuclear transfer. Anterior pituitary cells isolated from an adult male Shiba goat were transfected with a DNA fragment containing the enhanced green flourescent protein gene and the puromycin resistance gene. A single donor cell was inserted into the perivitelline space of each enucleated oocyte and fusion was induced with one electric pulse of 20 V for 10 µs. The SCNT goat eggs were cultured in chemically defined medium at 38.5°C in 5% CO2, 5% O2, 90% N2 for 9 days. By LFA, 396 oocytes were collected from a total of 30 females. After removal of cumulus cells, 64% of them extruded the first polar body. The percentage of SCNT goat eggs produced using in vivo matured oocytes which developed to the blastocyst stage (20–21%) was significantly higher (P < 0.05) than that produced with in vitro matured oocytes (3–8%). 相似文献
4.
5.
MINORU TANAKA SHIZUO KIMURA TAKAFUMI FUJIMOTO SUZU SAKAO ETSURO YAMAHA KATSUTOSHI ARAI 《Fisheries Science》2003,69(1):176-180
ABSTRACT: In normally fertilized progeny of the kokanee salmon Oncorhynchus nerka , DNA content flow cytometry revealed that all the externally normal embryos were diploid, whereas abnormal embryos exhibited haplo-diploid, diplo-tetraploid and haplo-diplo-tetraploid mosaicisms, together with a few haploid and diploid individuals. When gynogenetic development was artificially induced by fertilization of eggs obtained from a female of the same kokanee brood stock with UV-irradiated sperm, haplo-diploid mosaics appeared most frequently. These mosaics were likely to happen by certain cytological events, such as meiotic or mitotic errors during the process of maturation, fertilization or early cleavage. 相似文献
6.
7.
Yuri ABE Tomokazu TAMURA Shiho TORII Shiho WAKAMORI Makoto NAGAI Kazuya MITSUHASHI Junki MINE Yuri FUJIMOTO Naofumi NAGASHIMA Fumi YOSHINO Yukihiko SUGITA Takushi NOMURA Masatoshi OKAMATSU Hiroshi KIDA Yoshihiro SAKODA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2016,78(1):61-70
In our previous study, we genetically analyzed bovine viral diarrhea viruses (BVDVs)
isolated from 2000 to 2006 in Japan and reported that subgenotype 1b viruses were
predominant. In the present study, 766 BVDVs isolated from 2006 to 2014 in Hokkaido,
Japan, were genetically analyzed to understand recent epidemics. Phylogenetic analysis
based on nucleotide sequences of the 5′-untranslated region of viral genome revealed that
766 isolates were classified as genotype 1 (BVDV-1; 544 isolates) and genotype 2 (BVDV-2;
222). BVDV-1 isolates were further divided into BVDV-1a (93), 1b (371) and 1c (80)
subgenotypes, and all BVDV-2 isolates were grouped into BVDV-2a subgenotype (222). Further
comparative analysis was performed with BVDV-1a, 1b and 2a viruses isolated from 2001 to
2014. Phylogenetic analysis based on nucleotide sequences of the viral glycoprotein E2
gene, a major target of neutralizing antibodies, revealed that BVDV-1a, 1b and 2a isolates
were further classified into several clusters. Cross-neutralization tests showed that
BVDV-1b isolates were antigenically different from BVDV-1a isolates, and almost BVDV-1a,
1b and 2a isolates were antigenically similar among each subgenotype and each E2 cluster.
Taken together, BVDV-1b viruses are still predominant, and BVDV-2a viruses have increased
recently in Hokkaido, Japan. Field isolates of BVDV-1a, 1b and 2a show genetic diversity
on the E2 gene with antigenic conservation among each subgenotype during the last 14
years. 相似文献
8.
9.
Yuuto KAWASHIMA Ayako FUJIMOTO Morihiro SAITO Osamu MIKAMI Yoshiharu ISHIKAWA Koichi KADOTA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(6):968
The histology and immunohistochemistry of pleomorphic and conventional epithelioid mesotheliomas were examined. The former was detected in two young calves aged 2 and 4 months and was characterized by pleomorphic and atypical cells with decreased expression of cytokeratin 7 (CK7). In contrast, the latter was found in a 31-month-old heifer, consisting of tumor cells uniform in size and shape with CK7 expression in nearly all cells. Production of collagen by tumor cells was demonstrated in both histological types, and was considered to be characteristic of bovine epithelioid mesothelioma. Pleomorphic mesothelioma is far more pleomorphic and mitotically active than conventional mesothelioma, and its normal counterpart may be immature mesothelial cells with high proliferation potential, which exist in fetal life and early calfhood. 相似文献
10.
Masayuki YAMAMOTO Hiroyasu MAKINO Jun-ichiro KOBAYASHI Osamu TOMINAGA 《Fisheries Science》2004,70(6):1098-1105
ABSTRACT: The abundance of food organisms and feeding habits of larval and juvenile Japanese flounder were examined during the period from May to August in 1999, 2000 and 2001 at the sandy Ohama beach, the central Seto Inland Sea. The food organisms collected with a sledge net consisted of 40 families from 18 orders, dominated by mysids, crangonids and gammarids. The mean densities of mysids, crangonid shrimp ( Crangon spp.), gammarids and fish were 2.74, 6.74, 2.91 and 0.15 individuals/m2 , respectively. The main prey of the flounder ( n = 202; range of total length 9.80–75.95 mm) was mysids and small crangonid shrimp (<14 mm in body length). Prey fish availability was low, as the density of fish was low. The small crangonid shrimp was abundant, and the large crangonid shrimp, which could prey on larval flounder, was not abundant. The crangonid shrimp was important not as a predator for the flounder but as prey. The flounder preferred epifaunal mysids, Nipponomysis ornata and Anisomysis ijimai , to sand-burrowing mysids, Iiella oshimai , and avoided crangonid shrimp. 相似文献