Paternity in horseshoe crabs when spawning in multiple-male groups

Unpaired or satellite male horseshoe crabs, Limulus polyphemus, are attracted to and often form a group around a pair (a female with an attached male) that is nesting in the high intertidal zone. These males are engaged in sperm competition. We observed nesting pairs and their associated satellites in the wild, collected and reared their eggs and used genetic markers to examine paternity. We found that the unpaired, satellite males are highly successful at fertilizing eggs; two satellites can leave the attached male with few fertilizations. Two satellites together are each as successful as one spawning with a pair. A satellite's location around the female greatly affects his success, and males compete for access to a position over the dorsal canal between the prosoma and opisthosoma of the female and under the front margin of the paired male where they are most likely to fertilize eggs. Although eggs and sperm retain their viability for some time after spawning, nearly all eggs are fertilized by the satellites that are around the nesting pair at the time of egg laying and by the attached male. A number of factors including beach current, female size and male behaviour affect the outcome of sperm competition in this externally fertilizing species. Copyright 2000 The Association for the Study of Animal Behaviour.     

Phenol-oxidase (laccase) activity in strains of the hyphomycete Chalara paradoxa isolated from olive mill wastewater disposal ponds

Production of laccase activity by nine strains of Chalara paradoxa isolated from olive mill wastewater disposal ponds were studied. Enzyme extracts obtained from cultured broths by adsorption on hydroxyapatite showed a single band of laccase activity on ABTS after polyacrylamide gel electrophoresis (PAGE). They showed small mobility differences, with molecular masses of 67 to 68 kDa. Enzymes from the different strains oxidized a variety of phenolic and non-phenolic substances, and they could be divided into two groups according to their relative activities on substrates. All laccases showed a dual pH dependence of activity, with a maximum in the range of pH 3.0 to 4.5 for ABTS, o-dianisidine and 2,6-dimethoxyphenol, and pH 6.0 (Group 1) or pH 6.5 (Group 2) for syringaldazine and other substrates. Optimal temperatures were in the range of 10 to 28 degrees C for two strains (maximum at 10 degrees C) and 10 to 37 degrees C for the rest. The different enzymes were partially inactivated by heating at 60 degrees C and totally inactivated at 70 degrees C. Laccases were stable in a pH range of 3.0 to 9.0 (except for strain 36A, which was partially inactivated at pH 3.0), but became inactivated at pH 2.0. Altogether these data suggest that Ch. paradoxa strains produce different laccase isoenzymes.     

Identification of lactobacillus delbrueckii and subspecies by hybridization probes and PCR

Three methods addressing two different target sites were compared for identification and differentiation of the subspecies Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus delbrueckii subsp. lactis/delbrueckii. A PCR method - three primer pairs that enable direct identification of the species and the two subspecies, respectively - was derived from a DNA fragment showing significant similarities to parts of the addAB genes of Bacillus sutbtilis. In addition, two oligonucleotide probes for the two subspecies were designed from that DNA region. Further, two oligonucleotide probes targeting the 16S rDNA were developed for subspecies differentiation by a one base-pair difference following identification of the species. Moreover, these probes were demonstrated to be applicable for in situ hybridization experiments. The results obtained by the different methods were in good agreement.     

Phosphorylation of GRK2 by protein kinase C abolishes its inhibition by calmodulin

G-protein-coupled receptor kinases (GRKs) are important regulators of G-protein-coupled receptor function. Two members of this family L, GRK2 and GRK5 L, have been shown to be substrates for protein kinase C (PKC). Whereas PKC-mediated phosphorylation results in inhibition of GRK5, it increases the activity of GRK2 toward its substrates probably through increased affinity for receptor-containing membranes. We show here that this increase in activity may be caused by relieving a tonic inhibition of GRK2 by calmodulin. In vitro, GRK2 was preferentially phosphorylated by PKC isoforms alpha, gamma, and delta. Two-dimensional peptide mapping of PKCalpha-phosphorylated GRK2 showed a single site of phosphorylation, which was identified as serine 29 by HPLC-MS. A S29A mutant of GRK2 was not phosphorylated by PKC in vitro and showed no phorbol ester-stimulated phosphorylation when transfected into human embryonic kidney (HEK)293 cells. Serine 29 is located in the calmodulin-binding region of GRK2, and binding of calmodulin to GRK2 results in inhibition of kinase activity. This inhibition was almost completely abolished in vitro when GRK2 was phosphorylated by PKC. These data suggest that calmodulin may be an inhibitor of GRK2 whose effects can be abolished with PKC-mediated phosphorylation of GRK2.     

Seasonal Variation in Female Response to Male Calling Song in the Field Cricket, Gryllus rubens

Conspicuous traits that make males attractive to females may make them vulnerable to predators. Females that approach conspicuous males may increase their risk of predation. This means that selection for reduced male conspicuousness in the presence of predators may be due to sexual selection resulting from altered female behavior in the face of increased predator risk. We examine this hypothesis in the field cricket, Gryllus rubens, in which male calling song attracts both conspecific females for mating and parasitoid flies (Ormia ochracea) which kill their hosts within a week. Female crickets are also parasitized by these flies as a result of associating with calling males. In northern Florida crickets that emerge in the spring are not subject to fly parasitism whereas autumn crickets encounter large numbers of flies. We predicted that autumn females should be less attracted to male song than spring females. We tested female response to male calls in a rectangular arena in which male calling song was broadcast from a speaker. Spring females readily approached the speaker but autumn females were less likely to approach and remain in the vicinity of the speaker. These results emphasize the importance of considering how risk affects the evolution of conspicuous male behavior both directly through its effect on the male and indirectly through its effect on female responses to males.     

Genetic diversity of Nubian ibex in comparison to other ibex and domesticated goat species

Capra nubiana is a wild ibex species that is in danger of extinction. This study aimed at assessing the genetic diversity and population structure of Nubian ibex (Capra nubiana, n?=?8) in comparison to Alpine ibex (Capra ibex, n?=?8), Bezoar ibex (Capra aegagrus, n?=?4), and domesticated Taggar goats (Capra aegagrus hircus, n?=?24). All animals were genotyped with the 50K goat SNP chip. Since commercial SNP chips are not designed for wild species, data analysis was done in two ways: (1) using all callable SNPs (33,698) and (2) with a reduced set of SNPs segregating within three out of four populations (662). Using these two sets of SNPs, the observed heterozygosity in Nubian ibex ranged from 0.02 to 0.44, in Alpine ibex from 0.01 to 0.38, and in Bezoar ibex from 0.13 to 0.38, when analyzing 33,698 or 662 SNPs, respectively. In domesticated Taggar goats, the values for the observed heterozygosity using all 33,698 callable SNPs and the reduced set of 662 SNPs were similar (0.40–0.41). Pairwise F_ST values for the differentiation between species ranged from 0.17–0.35 (Bezoar ibex vs. Taggar goats) to 0.47–0.91 (Bezoar vs. Alpine ibex), and was 0.33–0.90 between Bezoar and Nubian ibex, respectively, to the two sets of SNPs. The analysis of molecular variance among all animals revealed that 74–78% can be explained by differences between species, while the residual 22–26% result from differences among individuals, respectively. Cluster analysis of Nei’s genetic distance allowed to detected two distinct clusters comprising Nubian and Alpine ibex on one hand and Taggar goats and Bezoar ibex on the other hand, and clear separation of all four breeds. Principal component (PC) analysis confirmed and further refined the clusters. SNPs that contributed most to PC1 allowed us to identify genomic regions accounting for the distances between species. These regions contain known milk protein genes. The identification of milk protein genes as contributors to the differentiation between species provides insights into the domestication of wild Capra breeds.     

HOW AND WHEN DO LAMBS RECOGNIZE THE BLEATS OF THEIR MOTHERS?

ABSTRACT

In domestic sheep Ovis aries, the mother and the young display a preferential bond for each other that relies on multimodal inter-individual recognition. Lambs show a preference for their own dam shortly after birth, and this is important for their survival. The role of acoustic cues in this early preference for the mother is not clear. The aim of the present work was to analyze the timing of acoustic recognition of the mother and to identify the physical parameters used in the recognition of maternal bleats by the lamb.

In a first study, we investigated the ability of lambs to discriminate between the bleats of their own mother and an alien equivalent mother in a two-choice test. Both ewes were hidden behind a canvas sheet and lambs were not allowed to approach the dams closer than 1 m, thus preventing visual as well as olfactory perception. Tests were conducted 12 hr, 24 hr or 48 hr after birth (n=19 or 20/group). An indication of vocal discrimination was already present at 24 hr and at 48 hr lambs spent significantly more time near their mother than near the alien dam.

In a second step, we investigated which physical parameters of the bleats were important for recognition. For this, we conducted playback experiments with modified bleats at two weeks postpartum. Ours results show that lambs pay attention to a combination of various time, energy and frequency parameters: timbre (distribution of energy within the spectrum), amplitude and frequency modulations appear to be the most important parameters encoding the individual signature.

We conclude that vocal recognition between the ewe and her lamb plays an important role in the display of preferential mother-young bond from very early on. Our studies also demonstrate that the encoding of the individual signature is not limited to the frequency domain but rather involves a multiparametric encoding process.     

家庭氧疗配合呼吸操治疗慢性阻塞性肺疾病患者的疗效

目的：观察长期家庭氧疗配合呼吸操治疗慢性阻塞性肺疾病（COPD）的临床效果。、方法：选择本院收治的COPD患者80例,随机分为研究组和对照组,各40例,两组均给予常规治疗,研究组同时由医务人员指导给予家庭氧疗和呼吸操训练,随访1年．观察两组治疗前、治疗后6个月和1年肺功能,应用StGeorge’S呼吸问卷（SGRQ）评价生存质量、结果：研究组1年内急性发作1次5人,2次2人,3次及以上1人,对照组1年内急性发作1次9人,2次7人,3次及以上4人（P〈0．05）;研究组治疗后6个月、1年用力肺活量（FVC）、第1秒用力呼气容积（FEVl）和FEVl／FVC均明显升高（P〈0．05）,对照组治疗后6个月、1年FVC、FEVI／FVC与治疗前比较无统计学差异（P〉0．05）;研究组治疗后6个月、1年SGRQ明显降低（P〈0．05）,对照组治疗后6个月、1年SGRQ与治疗前比较无统计学差异（P〉0．05）．结论：家庭氧疗配合呼吸操能明显改善COPD患者肺功能,延缓患者肺功能恶化,提高患者生存质量。     

The parasitic mite <Emphasis Type="Italic">Varroa destructor</Emphasis> affects non-associative learning in honey bee foragers, <Emphasis Type="Italic">Apis mellifera</Emphasis> L.

The parasitic mite Varroa destructor influences flight behavior, orientation and returning success of forager honeybees (Apis mellifera) infested as adults. As impaired orientation toward the nest entrance might be due to deficiency in recognition and responsiveness to stimuli in the environment, we examined effects of V. destructor on sensory responsiveness, non-associative and associative learning of honey bee foragers by using proboscis extension reaction paradigm (PER). Although infested and uninfested workers were initially equally responsive to different concentrations of sugar water, we found differences in non-associative learning. In habituation, PER to repeated sugar stimulation of the antennae occurred faster in infested foragers compared to uninfested foragers. In sensitization, infested foragers showed a lower response to an odor stimulus following sugar stimulation than non-infested foragers. Differences in non-associative paradigms were more pronounced in bees with lower responsiveness to sucrose. In conditioning learning experiments, a significant reduction in proboscis extension response was found 1 min but not 12 min after a single conditioning trial indicating that V. destructor predominantly affects the non-associative components of learning and its underlying neural and molecular processes. Jasna Kralj and Axel Brockmann have contributed equally to this study.     

儿童过敏性紫癜早期肾损伤中VCAM-1的临床意义

目的：探讨血管细胞粘附分子-1（VCAM-1）的检测在儿童过敏性紫癜（AP）早期肾损伤中的临床意义。方法：选择明确诊断为AP 患儿85 例,均为早期无肾损害的AP病儿。根据第七版诸福棠实用儿科学有关章节的诊断标准和随访结果,进一步将研究对象分为有肾损害AP 为APN 组,无肾损害AP为AP 组,于同时间、同群体中选择健康儿童35 名为对照组。应用ELISA 法分别检测三组患儿早期无肾损害时血VCAM-1 的含量,分析血VCAM-1在儿童过敏性紫癜早期肾损伤中的临床意义。结果：APN 组血VCAM-1 水平均高于AP组和正常对照组;AP 组亦高于正常对照组,差异均有统计学意义（P〈0.01）。结论：对早期无肾损害的AP病儿,检测血浆VCAM-1 对AP发生APN 的预后诊断有重要的临床意义。