瓦屋山国家森林公园锄足蟾科6种的繁殖鸣声特性

在地处四川省洪雅县的瓦屋山国家森林公园录取了锄足蟾科 6种的繁殖期求偶鸣叫声。它们分隶 4属 ,即角蟾属 (Megophrys)、齿蟾属 (Oreolalax)、齿突蟾属 (Scutiger)和掌突蟾属 (Leptolalax)。在IBMPC上用“SIGNAL”软件 (EngineeringDesign ,USA)对获取的鸣声资料进行分析 ,分析的频率范围设置为 0～ 10kHz。声学分析结果表明 :峨山掌突蟾 (L oshanensi) ,小角蟾 (M minorr) ,角蟾 1种 (M sp) ,金顶齿突蟾[S (S )chintingensis],峨眉齿蟾 (O omeimontis)和无蹼齿蟾 (O schmidti)的主能峰频率平均值分别是45 2 1 9、 34 5 6 4、 2 2 93 8、 10 76 5、 10 71 0和 1849 4Hz ,每声持续时间的平均值分别是 46 2、 90 8、 99 6、72 2、 78 8和 110 3ms ,声距的平均值分别是 140 4、 2 5 3 0、 6 81 4、 15 17 7、 46 1 3和 6 19 5ms。单因子方差分析结果表明主能峰频率、每声持续时间和各声距在 6个种间差异极显著 (P <0 0 1)。LSD法多重比较的结果指出金顶齿突蟾和峨眉齿蟾间的主能峰频率无显著差异 (P =0 917>0 0 5 ) ;在每声持续时间上 ,只有峨山掌突蟾与小角蟾、角蟾 1种、峨眉齿蟾、无蹼齿蟾间差异极显著 (P <0 0 1) ;在声距上 ,峨山掌突蟾与小角蟾间无显著差异 ,角蟾 1种与无蹼齿蟾之间、峨     

Molecular cloning and developmental expression of Tlx (Hox11) genes in zebrafish (Danio rerio)

Tlx (Hox11) genes are orphan homeobox genes that play critical roles in the regulation of early developmental processes in vertebrates. Here, we report the identification and expression patterns of three members of the zebrafish Tlx family. These genes share similar, but not identical, expression patterns with other vertebrate Tlx-1 and Tlx-3 genes. Tlx-1 is expressed early in the developing hindbrain and pharyngeal arches, and later in the putative splenic primordium. However, unlike its orthologues, zebrafish Tlx-1 is not expressed in the cranial sensory ganglia or spinal cord. Two homologues of Tlx-3 were identified: Tlx-3a and Tlx-3b, which are both expressed in discrete regions of the developing nervous system, including the cranial sensory ganglia and Rohon-Beard neurons. However, only Tlx-3a is expressed in the statoacoustic cranial ganglia, enteric neurons and non-neural tissues such as the fin bud and pharyngeal arches and Tlx-3b is only expressed in the dorsal root ganglia.     

Non-cell autonomous requirement for the bloodless gene in primitive hematopoiesis of zebrafish

Vertebrate hematopoiesis occurs in two distinct phases, primitive (embryonic) and definitive (adult). Genes that are required specifically for the definitive program, or for both phases of hematopoiesis, have been described. However, a specific regulator of primitive hematopoiesis has yet to be reported. The zebrafish bloodless (bls) mutation causes absence of embryonic erythrocytes in a dominant but incompletely penetrant manner. Primitive macrophages appear to develop normally in bls mutants. Although the thymic epithelium forms normally in bls mutants, lymphoid precursors are absent. Nonetheless, the bloodless mutants can progress through embryogenesis, where red cells begin to accumulate after 5 days post-fertilization (dpf). Lymphocytes also begin to populate the thymic organs by 7.5 dpf. Expression analysis of hematopoietic genes suggests that formation of primitive hematopoietic precursors is deficient in bls mutants and those few blood precursors that are specified fail to differentiate and undergo apoptosis. Overexpression of scl, but not bmp4 or gata1, can lead to partial rescue of embryonic blood cells in bls. Cell transplantation experiments show that cells derived from bls mutant donors can differentiate into blood cells in a wild-type host, but wild-type donor cells fail to form blood in the mutant host. These observations demonstrate that the bls gene product is uniquely required in a non-cell autonomous manner for primitive hematopoiesis, potentially acting via regulation of scl.     

Neonatal superior ovarian nerve transection disturbs the cyclic activity of the female rats

The neural pathway most related with ovarian steroidogenesis has been identified as the superior ovarian nerve (SON). This work constitutes the first study of the effects of early ovarian SON transection, which was performed in rats of 4 days of age (SON-t rats) to magnify the effects of the denervation. The rats were studied at the prepubertal (30 days), peripubertal (41 days) and adult cyclic in dioestrus (60 days) reproductive stages. The SON-t rats showed a delay of vaginal opening, a notable disruption of oestrous cyclicity, and a large number of corpora lutea. In all the stages, the circulating levels of FSH, prolactin and growth hormone were lower in SON-t rats than in controls, whereas LH did not vary. Serum androstenedione levels were higher in SON-t rats at 30 days and lower at 41 days, compared with control animals while no difference was observed at 60 days. Serum progesterone levels did not differ between control and SON-t, but serum oestradiol concentrations were higher in SON-t rats in all of the stages. At the peripubertal stage, there were fewer ovarian beta-adrenergic receptors in SON-t ovaries, associated with a rise in the ovarian content of norepinephrine, but no changes were observed in SON-t rats at 30 and 60 days with respect to the controls. The release of progesterone in vitro from luteal cell in SON-t rats at 60 days was reduced in basal condition and under ovine LH or FSH stimulation, when compared with control animals; while no difference was observed in presence of isoproterenol or androstenedione in the culture medium. In corpora lutea of SON-t rats at 60 days, no change was observed in the activity of 3beta-hydroxysteroid dehydrogenase (3beta-HSD), but the activity of 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD) was reduced, suggesting abnormal luteolysis in spite of the large number of corpora lutea. The interruption of innervation at an early age by SON transection is very important in the regulation of ovarian development in prepubertal and cyclic rats. The functional changes observed in the ovary suggest a possible alteration in the hypothalamic-hypophyseal axis.     

Talin is essential for integrin function in Drosophila

We show that the Drosophila gene rhea, isolated because its wing blister phenotype is typical of mutants affecting integrin function, encodes talin. Embryos deficient in talin have very similar phenotypes to integrin (betaPS) null embryos, including failure in germ band retraction and muscle detachment. We demonstrate that talin is not required for the presence of integrins on the cell surface or their localization at muscle termini. However, talin is required for formation of focal adhesion-like clusters of integrins on the basal surface of imaginal disc epithelia and junctional plaques between muscle and tendon cells. These results indicate that talin is essential for integrin function and acts by stably linking clusters of ECM-linked integrins to the cytoskeleton.     

RAC protein directs the complete removal of the 3' external transcribed spacer by the Pac1 nuclease

In Schizosaccharomyces pombe, interdependency in rRNA processing is mediated by a large protein complex (RAC) which contains independent binding sites for each of the transcribed spacers. The RAC complex exhibits no nuclease activity but dramatically alters the efficiency and specificity of the Pac1 nuclease, leading to the complete removal of the 3' ETS. Furthermore, the affinity of RAC protein for mutant 3' ETS correlates closely with in vivo effects on rRNA processing, and changes which disrupt RAC protein binding also inhibit Pac1 nuclease cleavage at the 3' end of the 25S rRNA sequence. The observations indicate that, in the presence of the RAC protein/3' ETS complex, cleavage by the RNase III-like homolog is not restricted to the known intermediate sites but also is directed at the 3' end of the 25S rRNA.     

Response to oxidative stress as a welfare parameter in swine

In pigs, the genetic selection for lean, large muscle blocks and fast growth has been linked to an increased prevalence of metabolic diseases such as porcine stress syndrome and mulberry heart disease. These diseases are associated with cardiovascular inadequacy, which may lead to oxidative stress. In the present study, reactive oxygen metabolites (ROMs) and the anti-oxidant power (OXY) in sera of different swine groups were investigated. The following groups were selected (each around 80 kg body weight): wild boars (WB), Cinta Senese (CS), and Landrace x Large White (LxLW), the latter as both specific pathogen-free (SPF) and intensively farmed animals. In addition, a group of LxLW agonic sows (AS) was also investigated; this group is known to be under oxidative stress. Two colorimetric micro-methods were used to measure ROMs and OXY; ROMs were expressed as mM H(2)O(2) and OXY as microM HOCl neutralised. Between groups, average ROM and OXY values were found to be significantly different by one-way ANOVA (P < 0.001). ROM levels were lower in WB (13.41 +/- 1.85) and CS (19.27 +/- 1.68), and highest in LxLW (42.00 +/- 1.36). OXY values ranged from 260.10 +/- 22.13 (WB) to 396.90 +/- 9.83 (LxLW). Only one swine group (the CS group) showed a significant, positive correlation between ROM and OXY values. The AS group even showed a negative correlation between ROM and OXY values. These results imply satisfactory environmental coping occurred only within the CS group. Results are discussed in the light of animal welfare legislation, food safety and consumers' protection.     

Pulmonary type II cell hypertrophy and pulmonary lipoproteinosis are features of chronic IL-13 exposure

Interleukin (IL)-13, a key mediator of Th2-mediated immunity, contributes to the pathogenesis of asthma and other pulmonary diseases via its ability to generate fibrosis, mucus metaplasia, eosinophilic inflammation, and airway hyperresponsiveness. In these studies, we compared surfactant accumulation in wild-type mice and mice in which IL-13 was overexpressed in the lung. When compared with littermate controls, transgenic animals showed alveolar type II cell hypertrophy under light and electron microscopy. Over time, their alveoli also filled with surfactant in a pulmonary alveolar proteinosis pattern. At the same time, prominent interstitial fibrosis occurs. Bronchoalveolar lavage fluid from these mice had a three- to sixfold increase in surfactant phospholipids. Surfactant proteins (SP)-A, -B, and -C showed two- to threefold increases, whereas SP-D increased 70-fold. These results indicate that IL-13 is a potent stimulator of surfactant phospholipid and surfactant accumulation in the lung. IL-13 may therefore play a central role in the broad range of chronic pulmonary conditions in which fibrosis, type II cell hypertrophy, and surfactant accumulation occur.     

Extensive multiple test centre evaluation of the VecTest malaria antigen panel assay

To determine which species and populations of Anopheles transmit malaria in any given situation, immunological assays for malaria sporozoite antigen can replace traditional microscopical examination of freshly dissected Anopheles. We developed a wicking assay for use with mosquitoes that identifies the presence or absence of specific peptide epitopes of circumsporozoite (CS) protein of Plasmodium falciparum and two strains of Plasmodium vivax (variants 210 and 247). The resulting assay (VecTest Malaria) is a rapid, one-step procedure using a 'dipstick' test strip capable of detecting and distinguishing between P. falciparum and P. vivax infections in mosquitoes. The objective of the present study was to test the efficacy, sensitivity, stability and field-user acceptability of this wicking dipstick assay. In collaboration with 16 test centres world-wide, we evaluated more than 40 000 units of this assay, comparing it to the standard CS ELISA. The 'VecTest Malaria' was found to show 92% sensitivity and 98.1% specificity, with 97.8% accuracy overall. In accelerated storage tests, the dipsticks remained stable for > 15 weeks in dry conditions up to 45 degrees C and in humid conditions up to 37 degrees C. Evidently, this quick and easy dipstick test performs at an acceptable level of reliability and offers practical advantages for field workers needing to make rapid surveys of malaria vectors.