幼龄红嘴相思鸟小脑皮质组织学结构

为了探讨不同日龄幼龄红嘴相思鸟(Leiothrix lutea)小脑皮质的组织学结构变化,分别以1、5、9日龄红嘴相思鸟为研究对象,通过H.E和甲苯胺蓝法进行染色,光镜下观察红嘴相思鸟小脑冠状切面的显微结构。结果显示,1日龄时,小脑皮层由外颗粒层(EGL)、浦肯野细胞层(PCL)和内颗粒层(IGL)3层构成,外颗粒层较厚且清晰,而浦肯野细胞层和内颗粒层界限不清楚;5日龄和9日龄时,小脑皮质均可见外颗粒层、分子层(ML)、浦肯野细胞层和内颗粒层4层结构。对3个日龄红嘴相思鸟小脑皮质各层厚度进行单因素方差分析,随日龄增长,小脑皮质、分子层和内颗粒层厚度极显著增厚(P0.01),浦肯野细胞体积也极显著增加(P0.01);外颗粒层厚度变化不明显(P0.05),呈现先增厚后变薄的趋势,与皮质厚度的比例逐渐减小。研究表明,幼龄红嘴相思鸟在出生后,随日龄增长,小脑皮质层逐渐发育成熟。内颗粒层与外颗粒层的相对变化规律表明,内颗粒层细胞是由外颗粒层迁移而来的。     

变温条件下红嘴相思鸟黄体生成素分泌节律的可塑性及个体间变异

鸟类的生殖内分泌主要受光周期调控,在全球气候变化的背景下,鸟类生殖内分泌轴(HPG)分泌节律适应温度变化的可塑性及个体间变异则决定了种群适应气候变化的微进化潜能。以黄体生成素(LH)为指标研究了红嘴相思鸟HPG轴分泌节律的温度可塑性及个体间变异。研究结果表明:(1)温度升高可引起红嘴相思鸟LH分泌活动。(2)高温组和低温组红嘴相思鸟血浆LH水平均存在个体差异,高温组的个体间变异总体上大于低温组。一些个体具有较大的HPG轴可塑性,能够提前分泌LH。研究结果表明温度升高条件下,红嘴相思鸟HPG轴活动具有提前的可能性,且种群内存在个体间差异,一些个体可提前启动生殖,进而适应可能出现的环境变化。为探讨鸟类适应气候变化的微进化潜能提供了参考信息。     

Assessment of quality control parameters during mass rearing of a pupal colour genetic sexing strain of the Mediterranean fruit fly

Quality control charts were employed to monitor the quality of several parameters during mass rearing of the T : Y(wp ⁺)30C strain of Ceratitis capitata (Wiedemann), in which male and female flies emerge from brown and white puparia, respectively. Egg hatch and pupal recovery in this genetic sexing strain were below that reported for a wild-type Sohag strain, whereas pupal size, adult emergence and flight ability were higher. The overall recovery from eggs to adult flies capable of flight was similar in the two strains but egg production in T:Y(wp ⁺)30C was reduced to about 56% of that of Sohag. The quality control charts showed an acceptable level of variation within sets of data but the level between data sets was occasionally out of control. This indicated the presence of uncontrolled conditions during the rearing process, possibly arising from variations in the quality of the larval diet. It is concluded that the quality of T : Y(wp ⁺)30C renders this strain suitable for mass rearing in sterile insect technique (SIT) programmes requiring the elimination of the female flies prior to the release of sterilized males. The next step should involve further quality assessments both under field cage and under field release conditions. The importance of optimal and standardized dietary conditions is stressed in relation to the quality of mass reared medflies.

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Résumé Des normes de qualité ont été utilisées pour relever la valuer de plusieurs paramètres lors de l'élevage industriel de la souche T : Y(wp ⁺)30C de C. capitata Wied. dont les mâles et les femelles émergent respectivement de pupes brunes et blanches. Les taux d'éclosion et d'obtention de pupes sont plus faibles avec cette souche qu'avec la souche souvage Sohag; par contre, la taille des pupes, le taux d'émergence des adultes et l'aptitude au vol étaient plus élevés. La fréquence totale des adultes capables de voler par rapport au nombre initial d'ufs a été de 0,297 contre environ 0,311 pour Sohag. Cependant, la production d'ufs a été réduite à environ 56% de celle de Sohag. Les tableaux de contrôle de la qualité ont révélé un niveau de variation acceptable à l'interieur rieur des lots de données, mais la variabilité entre les lots excédait les normes admissibles. Ceci implique des paramètres incontrôlés pendant l'élevage de masse, probablement liés à des variations de la qualité de l'aliment. On peut en conclure que la qualité de la souche T : Y(wp ⁺)30C la rend utilisable pour un élevage de masse dans des programmes d'utilisation d'insectes stériles (SIT) exigeant l'élimination des femelles avant le lâcher de mâles stériles. La prochaine étape impliquera de nouvelles épreuves de qualité dans des cages en champ et dans les conditions de libération dans la nature. L'importance des conditions optimales d'une alimentation standardisée est soulignée par la qualité des mouches obtenues en élevage de masse.

     

Heteroduplex molecules cause sexing errors in a standard molecular protocol for avian sexing

Molecular methods are a necessary tool for sexing monomorphic birds. These molecular approaches are usually reliable, but sexing protocols should be evaluated carefully because biochemical interactions may lead to errors. We optimized laboratory protocols for genetic sexing of a monomorphic shorebird, the upland sandpiper (Bartramia longicauda), using two independent sets of primers, P2/P8 and 2550F/2718R, to amplify regions of the sex‐linked CHD‐Z and CHD‐W genes. We discovered polymorphisms in the region of the CHD‐Z intron amplified by the primers P2/P8 which caused four males to be misidentified as females (n = 90 mated pairs). We cloned and sequenced one CHD‐W allele (370 bp) and three CHD‐Z alleles in our population: Z° (335 bp), Z′ (331 bp) and Z″ (330 bp). Normal (Z°Z°) males showed one band in agarose gel analysis and were easily differentiated from females (Z°W), which showed two bands. However, males heterozygous for CHD‐Z alleles (Z′Z″) unexpectedly showed two bands in a pattern similar to females. While the Z′ and Z″ fragments contained only short deletions, they annealed together during the polymerase chain reaction (PCR) process and formed heteroduplex molecules that were similar in size to the W fragment. Errors previously reported for molecular sex‐assignment have usually been due to allelic dropout, causing females to be misidentified as males. Here, we report evidence that events in PCRs can lead to the opposite error, with males misidentified as females. We recommend use of multiple primer sets and large samples of known‐sex birds for validation when designing protocols for molecular sex analysis.     

Overview of sexing sperm

Hundreds of thousands of off springs have been born as a result of AI with sexed sperm. Although this technology has been used for many species, the overwhelming majority of pregnancies have been in cattle, nearly all as a result of sperm that were sexed and subsequently frozen. The technology for sexing sperm has not changed greatly in the past 7 years, but refinements have speeded up the process and reduced damage to sperm. The process of commercialization of sexed sperm has accelerated recently. However, this technology is characterized by high costs, complexity of implementation and lower pregnancy rates than with control sperm. Nevertheless, sexed, frozen bovine sperm are being produced commercially in many countries, although from a limited number of bulls. The main application of sexed sperm to date has been to breed dairy heifers to produce female calves. Because of the slow speed of sexing sperm, fewer sperm are used per insemination dose of sexed than conventional sperm, and pregnancy rates with this product are often only slightly decreased. Successful use of sexed sperm requires excellent management of cattle, careful handling of sperm and use of skilled inseminators. As costs decline, sexed sperm will be used increasingly for cattle breeding, horse breeding and niche applications in other species.     

Improving language and literacy is a matter of time

Developmental deficits that affect speech perception increase the risk of language and literacy problems, which can lead to lowered academic and occupational accomplishment. Normal development and disorders of speech perception have both been linked to temporospectral auditory processing speed. Understanding the role of dynamic auditory processing in speech perception and language comprehension has led to the development of neuroplasticity-based intervention strategies aimed at ameliorating language and literacy problems and their sequelae.     

Mouth colour is a reliable signal of need in begging canary nestlings

Begging passerine chicks display brightly coloured mouths as they solicit food from their parents. Despite a range of hypotheses, the function of vivid nestling mouth colour remains unknown. Here I report that mouth colour functions as a signal of need in canary nestlings, in the days immediately following hatching. Changes in mouth colour accurately reflect a nestling''s state of need: the more food deprived the chick, the more intensely coloured its mouth. In controlled experiments with two nestlings, parents were offered the opportunity to choose which nestling to feed. When the mouth colour of one offspring was artificially reddened using food colouring, parents gave it more food. These results demonstrate a novel function for nestling mouth colour and are consistent with recent models of the resolution of parent–offspring conflict.     

Molecular sexing of African rhinoceros

We report the development of a fast and reliable PCR-based method for sex identification of African Rhinoceros (Ceratotherium simum and Diceros bicornis) that could easily be incorporated into fluorescent short tandem repeat (STR) profiling. A single primer pair, consisting of a fluorescently labelled forward primer and an unlabelled reverse primer, is used to co-amplify homologous fragments of a zinc finger (ZF) protein intron which exhibits size polymorphism between the X and Y chromosomes. In both species, the amplified ZFX and ZFY amplicons differ in size by 7 bp and can thus be differentiated by capillary electrophoresis. Blood, tissue, horn, and faecal samples were correctly sexed using this method. Cross species testing also demonstrated that this method could be used to sex Indian rhinoceros (Rhinoceros unicornis) samples.     

红嘴相思鸟的消化系统形态学研究

对10只(6♀4♂)红嘴相思鸟消化系统的形态结构进行了较为系统的解剖与观察,并对各器官进行了测量.结果表明,红嘴相思鸟舌前端有刺毛状结构,后端有一排尖端后指的栉状突;咽有不规则乳突,食管较细,无明显可见的嗉囊;腺胃内壁粘膜上均匀分布小而多的圆形乳突,肌胃发达,内有黄色革质层;肠道总长约为体长的0.94倍.     

The diet of a declining Red-billed Chough Pyrrhocorax pyrrhocorax population on Islay,Scotland

Capsule: We quantify Red-billed Chough Pyrrhocorax pyrrhocorax diet from faecal samples collected on Islay. Dung invertebrates formed the majority of prey biomass in dune pasture and Tipulid larvae in mixed pasture but Aphodius larvae were scarce in the diet, whereas they had been a major component in the 1980s. There are management implications from the indication of a reduction in availability of preferred food.     

Diet of the Red-billed Chough Pyrrhocorax pyrrhocorax in south-east Spain

A sample of 140 Red-billed Chough pellets (35 from each season) was collected from communal roosting sites in south-east Spain. In almost every pellet there were three distinct dietary fractions: animal, vegetable and mineral. The animal faction constituted nearly 50% of the pellet volume in each of the four seasons. Wild grains and cultivated cereals were the most important vegetable elements, while 60% of animal prey (n= 3484) were beetles (mainly Tenebrionidae). There was marked seasonal variation in the composition of both the vegetable and animal fractions, the latter associated mainly with variation in the occurrence of Orthoptera, Lepidoptera larvae and Formicidae. Mixed flocks of Choughs and Jackdaws were common in the study area though agonistic interspecific interactions were never observed. The diets of the two species differ in that Choughs eat more beetles and wild seeds, whilst Jackdaws prefer ants and cereals. These observations support the hypothesis that competition from Jackdaws is not responsible for the reduction in the Chough's range.     

Spectral sensitivities including the ultraviolet of the passeriform bird Leiothrix lutea

Spectral sensitivity functions of a passeriform bird, the Red-billed Leiothrix Leiothrix lutea (Timalidae) were determined in a behavioural test under different background illuminations.

Early neural development in vertebrates is also a matter of calcium

The calcium (Ca²⁺) signaling pathways have crucial roles in development from fertilization through differentiation to organogenesis. In the nervous system, Ca²⁺ signals are important regulators for various neuronal functions, including formation and maturation of neuronal circuits and long-term memory. However, Ca²⁺ signals are mainly involved in the earliest steps of nervous system development including neural induction, differentiation of neural progenitors into neurons, and the neuro-glial switch. This review examines when and how Ca²⁺ signals are generated during each of these steps with examples taken from in vivo studies in vertebrate embryos and from in vitro assays using embryonic and neural stem cells. Also discussed is the highly specific nature of the Ca²⁺ signaling pathway and its interaction with the other signaling pathways involved in early neural development.     

红嘴相思鸟鸣声的初步探讨

2005年4～10月,在四川省屏山县老君山自然保护区通过计算机声谱分析技术对红嘴相思鸟的鸣声进行了初步研究。结果表明：红嘴相思鸟具有报警、联络、警戒和惊叫4种鸣声;其中最常见的鸣声为联络鸣声,报警、警戒和惊叫3种鸣声是一个先后连续的鸣叫过程。通过红嘴相思鸟鸣声特点探讨了与其相应行为的关系。