We hypothesized that administration of hCG to recipients at embryo transfer (ET) would induce accessory CL, increase serum progesterone concentrations, and reduce early embryonic loss (as measured by increased transfer pregnancy rates). At three locations, purebred and crossbred Angus, Simmental, and Hereford recipients (n = 719) were assigned alternately to receive i.m. 1,000 IU hCG or 1 mL saline (control) at ET. Fresh or frozen-thawed embryos were transferred to recipients with a palpable CL on Days 5.5 to 8.5 (median = Day 7) of the cycle (Locations 1 and 2), or on Day 7 after timed ovulation (Location 3). Pregnancy diagnoses (transrectal ultrasonography) were done 28 to 39 d (median = 35 d) and reconfirmed 58 to 77 d (median = 67 d) post-estrus. At Location 1 (n = 108), ovaries were examined at pregnancy diagnosis to enumerate CL. More (P < 0.001) pregnant hCG-treated cows (69.0%) had multiple CL than pregnant controls (0%). Serum progesterone (ng/mL) determined at Locations 1 and 2 (n = 471) at both pregnancy diagnoses in pregnant cows was greater (P ≤ 0.05) after hCG treatment than in controls (first: 8.1 ± 0.9 vs 6.1 ± 0.8; second: 8.8 ± 0.9 vs 6.6 ± 0.7), respectively. Unadjusted pregnancy rates at the first diagnosis were 61.8 and 53.9% for hCG and controls. At the second diagnosis, pregnancy rates were 58.6 and 51.3%, respectively. Treatment (P = 0.026), embryo type (P = 0.016), and BCS (P = 0.074) affected transfer pregnancy rates. Based on odds ratios, greater pregnancy rates occurred in recipients receiving hCG, a fresh embryo (66.3 vs 55.5%), and having BCS >5 (62.3 vs 55.3%). We concluded that giving hCG at ET increased incidence of accessory CL, serum progesterone in pregnant recipients, and transfer pregnancy rates. Furthermore, we inferred that increased progesterone resulting from hCG-induced ovulation reduced early embryonic losses after transfer of embryos to recipients. 相似文献
Background: Flower colour variation among populations may result from the spatial variation of selective agents. The structure of phenotypic variation informs on the ecological processes related to this variation. Variation in floral traits is mainly attributed to variation in the pollinator fauna, while variation in vegetative traits is usually linked to abiotic factors or herbivores.
Aims: We investigated the geographical variation of flower colour (and correlated traits) in Gentiana lutea and the relationship with the variation in abiotic factors.
Methods: Phenotypic variation (flower colour, petal length, petal width, stalk length, leaf length, flower number, petal number and number of basal leaves) was assessed in 429 plants of 12 populations located at north-west Iberia. Additionally, we obtained data on the geographical coordinates, elevation, temperature, rainfall and radiation for each population.
Results: Populations mostly differed in flower colour, from orange to yellow from west to the east. Abiotic factors were unrelated to variation in either floral or vegetative traits.
Conclusions: Phenotypic variation among G. lutea populations does not result from adaptation to environmental factors. Other factors, such as historical events or selective pressure exerted by biotic interactions, might explain the flower colour variation in G. lutea along the Cantabrian Range. 相似文献
Ovaries from 14 female Hawaiian monk seals, O-24 yr of age, collected from the northwestern Hawaiian Islands were analyzed by gross and histological examination for the presence of corpora hemorrhagica (CH), lutea (CL), albicantia (CA), and dominant follicles. Seven seals, 5-24 yr of age, were mature females, and another seven seals, O-5 yr of age, were immature based on the presence or absence of CL and CA in the ovaries. Two 5-yr-old seals did not have CL and CA, but one J-yr-old and both 6-yr-old seals had CL or CA. In addition, the weight of the more active ovary increased at 5 yr of age, indicating that puberty in these female Hawaiian monk seals occurred about 5 yr of age. The total number of CL and CA was significantly correlated to the ovarian weight, but not age of the seals, indicating that visible CA of Hawaiian monk seals probably degenerate within a year. If an ovulation resulted in pregnancy, we assumed that the resulting CL from that pregnancy persisted throughout gestation and regressed approximately 2 yr after ovulation. However, the CL of pregnancy were not easily differentiated from cyclic CL that did not result in pregnancy. Four of seven mature seals were clearly polyestrous from the analyses of their ovaries and reproductive histories. The remaining three seals were pregnant in previous consecutive years, and we could not positively determine whether they were also polyestrous. The ovaries from Hawaiian monk seals had unusually large, rounded granular cells containing the aging pigment, lipofuscin. These cells were located between loose fibrous tissues in all regressing CL and CA but were not present in any CH. 相似文献
A new mannose-binding lectin was isolated from Sternbergia lutea bulbs by affinity chromatography on an α(1-2)mannobiose-Synsorb column and purified further by gel filtration. This lectin
(S. lutea agglutinin; SLA) appeared homogeneous by native-gel electrophoresis at pH 4.3, gel filtration chromatography on a Sephadex
G-75 column, and SDS-polyacrylamide gel electrophoresis, These data indicate that SLA is a dimeric protein (20 kDa) composed
of two identical subunits of 10 kDa which are linked by non-covalent interactions.
The carbohydrate binding specificity of the lectin was investigated by quantitative precipitation and hapten inhibition assays.
It is an α-D-mannose-specific lectin that interacts to form precipitates with various α-mannans, galactomannan and asialo-thyroglobulin,
but not with α-glucans and thyroglobulin. Of the monosaccharides tested only D-mannose was a hapten inhibitor of the SLA-asialothryroglobulin
precipitation system, whereas D-glucose, D-galactose and L-arabinose were not. The lectin appears to be highly specific for
terminal α(1-3)-mannooligosaccharides. The primary structure of SLA appears to be quite similar to that of the snow drop (Galanthus nivalis) bulb lectin which is a mannose-binding lectin from the same plant family Amaryllidaceae. The N-terminal 46 amino acid sequence
SLA showed 7% homology with that of GNA. Abbreviations: AAA, Allium ascalonicum agglutinin (shallot lectin); ASA, Allium sativum
agglutinin (garlic lectin); AUA, Allium ursinum agglutinin (ramsons lectin); DAP, 1,3-diaminopropane; GNA, Galanthus nivalis
agglutinin (snowdrop lectin); HHA, Hippeastrum hybr. agglutinin (amaryllis lectin); LOA, Listera ovata agglutinin (orchid
twayblade lectin); NPA, Narcissus pseudonarcissus agglutinin (daffodil lectin); PAGE, polyacrylamide gel electrophoresis;
PBS, phosphate-buffered saline, SLA, Sternbergia lutea agglutinin; SDS, sodium dodecyl sulfate; Me, methyl; Bn, benzyl; PNP,
p-nitrophenyl.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
New blue whale ovarian corpora data from illegal Soviet catches in the Southern Hemisphere and northern Indian Ocean were recovered from the original logbooks. Catches north of 52°S were assumed to be pygmy blue whales ( Balaenoptera musculus brevicauda , n = 1,272); those south of 56°S were assumed to be Antarctic (true) blue whales ( B. m. intermedia , n = 153). Three probable Antarctic blue whales north of 52°S were excluded. Lengths at which 50% and 95% of females become sexually mature ( L 50 and L 95) were estimated from a Bayesian logistic model. These estimates are more precise than previous Japanese estimates because Soviet catches below the legal minimum of 70 ft (21.3 m) were 32 times greater. For pygmy blue whales L 50 was 19.2 m (95% interval 19.1–19.3 m) and L 95 was 20.5 m (95% interval 20.4–20.7 m). Antarctic L 50 (23.4 m, 95% interval 22.9–23.9 m) was much longer than L 50 for pygmy blue whale regions (18.4–19.9 m). The median L 50 for the northern Indian Ocean was 0.5–0.6 m shorter than for pygmy blue whales from other regions; although statistically significant, these small length differences provide little support for northern Indian Ocean blue whales being a separate subspecies, B. m. indica . 相似文献