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311.
The New Zealand endemic bat family Mystacinidae comprises just two Recent species referred to a single genus, Mystacina. The family was once more diverse and widespread, with an additional six extinct taxa recorded from Australia and New Zealand. Here, a new mystacinid is described from the early Miocene (19–16 Ma) St Bathans Fauna of Central Otago, South Island, New Zealand. It is the first pre-Pleistocene record of the modern genus and it extends the evolutionary history of Mystacina back at least 16 million years. Extant Mystacina species occupy old-growth rainforest and are semi-terrestrial with an exceptionally broad omnivorous diet. The majority of the plants inhabited, pollinated, dispersed or eaten by modern Mystacina were well-established in southern New Zealand in the early Miocene, based on the fossil record from sites at or near where the bat fossils are found. Similarly, many of the arthropod prey of living Mystacina are recorded as fossils in the same area. Although none of the Miocene plant and arthropod species is extant, most are closely related to modern taxa, demonstrating potentially long-standing ecological associations with Mystacina.  相似文献   
312.
The hereditary spastic ataxias (HSA) are a group of clinically heterogeneous neurodegenerative disorders characterized by lower-limb spasticity and generalized ataxia. HSA was diagnosed in three unrelated autosomal dominant families from Newfoundland, who presented mainly with severe leg spasticity, dysarthria, dysphagia, and ocular-movement abnormalities. A genomewide scan was performed on one family, and linkage to a novel locus for HSA on chromosome 12p13, which contains the as-yet-unidentified gene locus SAX1, was identified. Fine mapping confirmed linkage in the two large families, and the third, smaller family showed LOD scores suggestive of linkage. Haplotype construction by use of 13 polymorphic markers revealed that all three families share a disease haplotype, which key recombinants and overlapping haplotypes refine to about 5 cM, flanked by markers D12S93 and GATA151H05. SAX1 is the first locus mapped for autosomal dominant HSA.  相似文献   
313.
314.
In response to cues signifying the approach of winter, adult Artemia franciscana produce encysted embryos that enter diapause. We show that respiration rates of diapause embryos collected from the field (Great Salt Lake, Utah) are reduced up to 92% compared with postdiapause embryos when measured under conditions of normoxia and full hydration. However, mitochondria isolated from diapause embryos exhibit rates of state 3 and state 4 respiration on pyruvate that are equivalent to those from postdiapause embryos with active metabolism; a reduction in these rates (15%-27%) is measured with succinate for two of three collection years. Respiratory control ratios for diapause mitochondria are comparable to or higher than those from postdiapause embryos. The P : O flux ratios are statistically identical. Our calculations suggest that respiration of intact, postdiapause embryos is operating close to the state 3 oxygen fluxes measured for isolated mitochondria. Cytochrome c oxidase (COX) activity is 53% lower in diapause mitochondria during one collection year; the minimal impact of this COX reduction on mitochondrial respiration appears to be due to the 31% excess COX capacity in A. franciscana mitochondria. Transmission electron micrographs of embryos reveal mitochondria that are well differentiated and structurally similar in both states. As inferred from the similar amounts of mitochondrial protein extractable, tissue contents of mitochondria in diapause and postdiapause embryos are equivalent. Thus, metabolic depression during diapause cannot be fully explained by altered properties of isolated mitochondria. Rather, mechanisms for active inhibition or substrate limitation of mitochondrial metabolism in vivo may be operative.  相似文献   
315.
The distribution of thiamine pyrophosphatase (TPPase) and acid phosphatase (AcPase) has been examined in resting parotid acinar cells as well as during decreased and increased secretory granule production. In resting acinar cells, TPPase activity was restricted to the trans Golgi saccules and AcPase activity was localized in GERL and immature secretory granules. Although secretory granule production is diminished during ethionine intoxication, no significant alteration in the distribution of either TPPase or AcPase was noted. However, marked changes in enzyme localization, especially of TPPase, occurred during accelerated secretory granule production. The alterations were essentially the same for all of the conditions studied (recovery from ethionine treatment, recovery from a protein depletion diet, secretory stimulation with isoproterenol, and postnatal maturation of the parotid gland). During maximal secretory granule production, TPPase activity was localized not only in the trans Golgi saccules, but also in GERL-like cisternae and immature secretory granules. The immature secretory granules were often in continuity with the GERL-like cisternae. At the same time that the TPPase activity was increased, the AcPase activity was frequently diminished. These modulations in enzyme activity provide evidence that GERL is derived from the trans Golgi saccule.  相似文献   
316.
Magainins, antimicrobial peptides secreted by granular glands of frog skin, may be related to the high resistance to infections of this epithelial surface. The oral mucosa of healthy individuals is another tissue in which infection is not frequent, probably owing to the activity of potent salivary and mucosal defense mechanisms. To investigate if magainin-like factors are a component of these oral defense mechanisms, human and animal minor (mucosal) and major salivary glands were examined by immunohistochemistry, using a polyclonal rabbit anti-magainin antibody. Cryostat sections of (para) formaldehyde-fixed tissues were incubated with the antibody and then stained with fluorescein-complexed anti-rabbit IgG. Specific staining was observed in the apical portion of the cytoplasm of ductal epithelial cells of human submandibular and labial salivary glands. Diffuse staining was present in submandibular acinar cells. Bovine, rat, hamster, and mouse tissues were unreactive. The presence of magainin-like substances in human salivary gland duct cells is consistent with reports of the occurrence of other biologically active substances in salivary gland ducts.  相似文献   
317.
The tissue and developmental specificities of the three Drosophila isoactins, originally identified in primary myogenic cultures and in the permanent Schneider L-2 cell line, have been investigated. Of these three isoactins (I, II, and III), actins I and II are stable and actin III is unstable. Two-dimensional polyacrylamide gel electrophoretic analyses of total cellular extracts after 1-h [(35)S]methionine pulses were performed on a large variety of embryonic, larval, and adult muscle and nonmuscle tissues. The results suggest that isoactins II and III are generalized cellular actins found in all drosophila cell types. Actin I, on the other hand, is muscle-associated and is found exclusively in supercontractile muscle (such as larval body wall and larval and adult viscera) including primary myogenic cell cultures. Although actin I synthesis is not detectable during very early embryogenesis, it is detectable by 25 h and actin I is a major stable actin in all larval muscle tissues. Actin I is synthesized in reduced amounts relative to the other actins in late third instar larvae but is again a major product of actin synthesis in the adult abdomen. A stable actin species with the same pI as actin III has been identified in the adult thorax and appears to be unique to flight muscle tissue. This new stable form of thoracic actin may be the result of a stabilization of the actin III found in other tissues or may be an entirely separate gene product.  相似文献   
318.
Human polymorphonuclear leukocyte elastase (PMN elastase) is inhibited by L-659,286 (7 alpha-methoxy-8-oxo-3-[[(1,2,5,6-tetrahydro-2-methyl-5,6-dioxo-1,2,4- triaz-in-3-yl)thio]methyl]-5-thia-1-aza-6R-bicyclo[4.2.O]oct-2-ene -2- pyrrolidine carboxamide-5,-dioxide) with a Ki of 0.4 microM. This inhibition is time-dependent, rapid, and only slowly reversible, with a t1/2 of greater than 3 days at 25 degrees C. L-659,286 is also highly selective for PMN elastase, as it does not inhibit thrombin, trypsin, papain, plasmin, chymotrypsin, or cathepsin G. L-659,286 administered intratracheally inhibits lung damage caused by administration via the same route of human PMN elastase into hamsters. In marmosets, L-659,286 is cleared from blood very rapidly after an intravenous injection but is recovered in bronchoalveolar lavage fluid for several hours after intratracheal administration.  相似文献   
319.

Background

In many studies, researchers may recruit samples consisting of independent trios and unrelated individuals. However, most of the currently available haplotype inference methods do not cope well with these kinds of mixed data sets.

Methods

We propose a general and simple methodology using a mixture of weighted multinomial (MIXMUL) approach that combines separate haplotype information from unrelated individuals and independent trios for haplotype inference to the individual level.

Results

The new MIXMUL procedure improves over existing methods in that it can accurately estimate haplotype frequencies from mixed data sets and output probable haplotype pairs in optimized reconstruction outcomes for all subjects that have contributed to estimation. Simulation results showed that this new MIXMUL procedure competes well with the EM-based method, i.e. FAMHAP, under a few assumed scenarios.

Conclusion

The results showed that MIXMUL can provide accurate estimates similar to those haplotype frequencies obtained from FAMHAP and output the probable haplotype pairs in the most optimal reconstruction outcome for all subjects that have contributed to estimation. If available data consist of combinations of unrelated individuals and independent trios, the MIXMUL procedure can be used to estimate the haplotype frequencies accurately and output the most likely reconstructed haplotype pairs of each subject in the estimation.  相似文献   
320.
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