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Nepal is a small, landlocked country with marked elevational variation from the Terai plains to the Himalayas. Here, four indigenous goat populations (Chyangra, Sinhal, Khari, and Terai) are raised at different elevations. This study aimed to clarify the genetic structure of these populations and how they are formed and propagated across the Himalayan region. We analyzed 136 Nepalese goats using mitochondrial (mt) DNA D-loop and sex-determining region Y (SRY) 3'-untranslated region (UTR) sequences, as well as 50 K SNP array data. The mtDNA haplogroups D (0.162) and G (0.03) were detected only in Chyangra, whereas haplogroup B was predominant in Sinhal (0.42), followed by Khari (0.260). Regarding SRY haplotypes, Y2B was detected in all populations, whereas Y1AB (0.42) was found only in Chyangra. Genome-wide SNP analysis showed that Chyangra was genetically related to Tibetan and Central Asian goats, while Terai resembled South Asian goats. Interestingly, Sinhal formed a distinct cluster, whereas Khari exhibited an admixed genetic structure. These findings suggest that Nepalese goats originate from at least three ancestral lineages and that an additional migration route may have existed through the southern Himalayas.
Dracunculus medinensis and D. insignis are morphologically indistinguishable. Experiments to test the susceptibility of various mammalian hosts to these two guinea worm species are described. Infective 3rd-stage larvae of D. medinensis were administered to each of four raccons (Procyon lotor): infective 3rd-stage larvae of D. insignis were administered to a rhesus monkey (Macaca mulatta), two dogs, two ferrets (Mustela putorius furo), and a marten (Martes americana). D. medinensis was not found in the raccoons when necropsies were performed on days 247, 283, 354, and 390 post-infection, respectively. Nine female D. insignis containing eggs, embryos, and motile 1st-stage larvae were found in the rhesus monkey 180 days post-infection. Lesions had not formed and the larvae were presumed to be immature and not yet infective as they were comparatively inactive and attempts to infect suitable copepods failed. D. insignis was not found in the dogs or the marten, although both ferrets were successfully infected. Variations in susceptibility of various mammalian species to the guinea worm are discussed together with comments on variations in migration routes and sites of emergence in hosts which may be partially refractory. D. insignis and D. medinensis may represent physiological strains of a single species, or they may in fact be two distinct species which have evolved in different geographical locations.
INTRODUCTION: Since their domestication, domestic sheep (Ovis aries) have been culturally and economically significant farming animals worldwide. Fat-tailed sheep serve as a unique genetic resource for understanding adipogenesis and adaptive evolution in livestock. OBJECTIVES: Several genomic analyses have been conducted on various sheep breeds to elucidate the genome and regulation mechanism of the fat tail trait, prior genomic studies have failed to reconcile conflicting evidence about the genetic basis of tail morphology, particularly regarding the roles of PDGFD and BMP2. METHODS: Here, we conducted whole-genome resequencing of 283 sheep, encompassing 66 domestic breeds and 5 wild ovine species, to investigate the domestication history and selection signatures of fat-tailed sheep. Additionally, we performed transcriptome sequencing on adipose tissue to identify differentially expressed genes and cellular assays to validate these results. RESULTS: Demographic analysis revealed that domestic sheep descended from Asiatic mouflon and fat-tailed sheep began to diverge from thin-tailed sheep approximately 4.4-7.5 thousand years ago in East Asia. Chinese indigenous sheep were classified into Mongolian, Kazakh, Tibetan, and Yunnan populations. The Yunnan population may have experienced more recent genetic introgression from wild species, rather than an independent domestication event. Moreover, many potential regions associated with the fat-tailed phenotype (DDI1, PDGFD, and BMP2) were identified by selective sweep and genome-wide association analyses. Additionally, a fine-scale analysis of fat-tailed and thin-tailed sheep revealed two novel mutations: a G/A missense variant of PDGFD (Chr15: 3900312) and a C/T missense variant of BMP2 (Chr13: 48462350), both of which were significantly associated with tail adiposity. Functional validation demonstrated that mutant A-PDGFD significantly activated PFGFD expression and reduced fat deposition compared to wildtype. The C-BMP2 mutant activated BMP2 expression and promoted preadipocyte fat deposition. CONCLUSION: Our study provides the first evidence that these genes jointly regulate fat tail development through complementary mechanisms: PDGFD promotes adipose expansion, whereas BMP2 modulates energy partitioning. These findings offer new insights into the evolutionary history of fat-tailed sheep and identify potential targets for precision breeding in small ruminants.
Because all stages of melanogenesis (premelanosome, melanosome and melanin granules) were found in intermediate cells of the rat stria vascularis, they can be classified as melanocytes. The marginal and basal cells of these rat specimens contained no pigment. Early in development, the melanocytes or future intermediate cells are located beneath the strial basal lamina. They penetrate this lamina to insert themselves between marginal cells. Both the melanocytes and marginal cells are believed to participate actively in the tissue rearrangements which ultimately bring the two cell types into intimate structural relationship. The ingrowing melanocytes and the mature, pigmented, intermediate cells which they form are frequently associated with blood vessels. Pretreatment with Dopa to enhance the melanin content of early melanocytes did not enable us to identify their route of migration into the stria.
The fate and routes of migration of infective larvae of Ascaridia columbae were studied in intravenously (i.v.) infected pigeons. Larvae were able to complete a trachael migration, and arrived at the small intestine where they established a patent infection. Granulomas were observed and histopathologically described in the lungs of i.v. infected birds.
Data on the mobility of radioactive products in biocoenoses are presented and the main routes of their migration are discussed. Data on radioactive contamination of food products of vegetable, animal and marine origin are mentioned. It has been demonstrated that technological processing of raw material and culinary preparation of food products results in a considerable reduction in their contamination. Data on the amounts of radioactive nuclides taken up by the human organism in consequence of local and global fallout of radioactive products are reported.
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In 32 patients neurological and radiological studies were done after spinal myelography using 5 ml of monoidostearate. The route and speed of elimination of the contrast medium remaining intrathecally have been observed over 2 years, establishing correlations with the way and conditions of administration. In the case of active lumbar drainage from the puncture channel after lumbar instillation of contrast medium or after lumbar puncture, a quick and sometimes massive extrathecal and extravertebral leakage, reaching 1/3 of the applied contrast medium, has been observed in 80%-90% of the cases during the first days and weeks. During the first year, the mean contrast medium elimination was 50%. In the case of a single cisternal instillation of contrast medium, no leakage was found, the elimination was 0-8-1-0 ml/year. The importance of "lumbar puncture drainage" becomes evident, as well as its activity which lasts up to 19 days. The possible routes of leakage (migration) of the contrast medium are discussed.
Human genetic admixture, involving the contact between two or more previously isolated populations, can be a complex process influenced by social dynamics. In this study, we aim to reconstruct complex admixture histories in São Tomé, an island in the Gulf of Guinea where the Portuguese established one of the first plantation-based slave societies. Since the 15th century, migration waves from Africa and Europe, slavery, marooning, and indentured labour led to profound demographic shifts and social stratification on the island. Examining 2.5 million SNPs newly genotyped in 96 São Toméans, we observed patterns of genetic differentiation that were more complex than those of other populations descended from enslaved Africans on either side of the Atlantic. Using local ancestry inference and Identical-by-Descent methods, we identified five genetic clusters in São Tomé and reconstructed shared ancestries between each cluster and 70 African and European population samples, including an extensive sample from the Cabo Verde archipelago. Our findings align with historical records, retracing the major slave trade routes and labour-driven migrations after the abolition of slavery. We also identified gene flow between recently admixed groups that were previously isolated on the island. We call this process, creating multiple layers of genetic ancestry in admixed genomes, nested admixture. We suggest that changing social structures in São Tomé transformed the genetic structure of its population and influenced the admixture process. This study demonstrates how successive admixture and isolation events during and after the Trans-Atlantic Slave Trade shaped extant genetic diversity patterns at local scale in Africa.
It is concluded that endolymphatic infusion of X-ray contrast substance in the presence of migrating tumor cells in lymphatic routes is inherent in a potential danger of tumor dissemination. Although getting of tumor cells in blood does not always result in metastases, nevertheless, a due account should be taken of the fact that lymphography is frequently performed in poor immunological resistance patients, preliminarily subjected to chemo- and radiotherapy. The decrease of immune resistance of the organism, in which the lymphatic system is of primary importance, is known to contribute per se to generalization of the tumor process. Another important conclusion is that the principal mass of tumor cells is ejected in the immediate period after endolymphatic injection of X-ray contrast substance. Thus, the cannulation of the thoracic duct during this period may prevent or reduce getting of massive amounts of tumor cells into the total blood flow.
Mechanisms of neutrophil infiltration into the rabbit alveolus have been investigated. Complement activation in the circulation induced pulmonary vascular margination but not a significant level of alveolar infiltration. Instillation of C5 fragments into the airways, however, attracted neutrophils into the alveolar airspaces. The anaphylatoxin-inactive fragment of C5, C5a des Arg, was found to be much more active in this regard than C5a. Furthermore, these fragments were shown to induce the production of a neutrophil-directed chemoctactic factor from pulmonary macrophages, raising the question of whether the C5a des Arg was acting directly to attract neutrophils or indirectly via the macrophage. To substantiate a possible role for C5 and C5 fragments in alveolitis, active C5 was demonstrated in lavage fluids, and macrophage-derived C5 cleaving enzymes have been described. Finally, a route of neutrophil infiltration via migration through the alveolar capillary wall into the interstitium is proposed, and subsequent penetration of the alveolar epithelium out into the airspace. (Am J Pathol 97:93--110, 1979).
The study of migration ecology is crucial for understanding the factors and pressures affecting migratory species. Here, we studied the migratory ecology of the little bustard (Tetrax tetrax), a steppe bird that has suffered a sharp decline over recent decades, mainly due to agricultural intensification. Using 105 adult birds tagged across the main Iberian regions where the species is present (Alentejo, Extremadura, Ebro Valley, Northern Plateau, Southern Plateau and Guadalquivir Valley), we analysed the ratio of migratory and resident birds in each population and assessed their connectivity during the three main migratory periods (summer, winter and pre-breeding). Additionally, we describe the features of the migrations recorded in terms of length, duration and day period. Our results corroborate that little bustards can be considered partial migrants across Iberia, although the proportion of residents versus migrants varied between populations: the Alentejo (94.74%) and Northern Plateau (93.75%) had the highest proportion of migrants, followed by Guadalquivir Valley (81.82%), Extremadura (65.38%), Southern Plateau (55.56%) and Ebro Valley (25.93%). Migratory connectivity varied between periods: the pre-breeding and summering migrations showed a trend to move northwards, while birds moved southwards for winter. Regarding the migratory corridors obtained from the 253 migrations identified, we found three main routes: one corridor that connects the Northern Plateau with the western part of the Southern Plateau and Extremadura, another one that connects the Southern Plateau, Extremadura, Alentejo and Guadalquivir Valley, and one corridor that concentrates migrations within the Ebro Valley, and between the Ebro Valley and the Southern Plateau. Finally, analyses showed that little bustards migrate at night through areas dominated by herbaceous cover (avoiding tree-covered land and water bodies) and of low elevation and terrain roughness. Our results highlight the importance of developing an international and inter-regional conservation strategy to protect not only the breeding and wintering quarters, but also this endangered species' migratory corridors, thus supporting the viability of the metapopulation.
The migration of mice peritoneal macrophages has been studied on agar plates. The migration of the macrophages from mice treated by the intra peritoneal route by a somatic antigen of Bacillus subtilis, was 37% less than the migration of the macrophage from control mice. The presence of the antigen in the gel did not modify the migration of macrophages in either treated or control mice. This confirms the non specific character of the activity of this antigen.
Quantitative histological methods were applied in a study of the migratory route of schistosomula within the definitive mammal host. The observations are consistent with an entirely intravascular mode of migration in the direction of blood flow. They do not support a trans-diaphragm route. Schistosomula can be identified in low numbers in systemic organs, in the left side of the heart and in the venous compartment of the pulmonary circulation. They were not observed penetrating the diaphragm or the capsule of the liver. No histopathological evidence was found to suggest that the tissue responses of previously unexposed hosts affect migrating schistosomula at any stage during migration. These non-specific tissue responses were marked only in the skin phase of migration.
The data supplied by analysis of more than 1 000 patients pointed to the wide range of the causal factors, the role of focal infections of the upper respiratory and digestive tracts and the mechanisms that interfere in the determinism of the bronchopulmonary suppurative syndrome, the septic particles migrating as a rule along the bronchogenic route.
The protection action of carotenoids against irreversible photodestruction was discovered in photosynthetic bacteria by Stanieda and coworkers. In green plant material it was found by Wolff and Witt (1969) Z. Naturforsch, 24b, 1031-1037 and (1972) Proc. 2nd. Int. Congr. Photosynthesis Res. Stresa (Forti, G., Avron, M. and Melandri, A., eds.), Vol. 2, pp. 931-936, Dr. W. Junk, N. V. Publ. The Hague) that the formation of special carotenoid triplet states (via very rapid energy transfer from excited chlorophylls) and their fast radiationless decay in tau1/2 approximately 3 microns is at least one mechanism for the protective action of carotenoids to irreversible photooxidation of the chlorophylls. Hence, it is anticipated that the same mechanism might be realized also in bacteria. The present study gives evidence for such a "triplet valve" to be established also in bacteria. This conclusion was derived from the following observations: 1. The light-induced difference spectrum shows a bleaching of a carotenoid at three characteristic wavelength between 400 and 500 nm. A positive peak around 533 nm indicates the formation of a carotenoid triplet state. 2. The absorption changes can be induced by red light which excites only bacteriochlorophyll. This indicates an energy transfer from bacteriochlorophyll to carotenoids. 3. The light-induced carotenoid triplets decay radiationless in 3 microns in air-saturated aqueous suspensions of the chromatophores. 4. The carotenoid triplet formation occurs only at actinic flash intensities where the photosynthesis becomes saturated. 5. Addition of dithionite, which blocks photosynthesis, markedly increases the extent of carotenoid triplet formation. The different types of exciton migration within the photosynthetic unit are discussed, especially the routes leading to the dissipation of excess excitation energy.
Range expansions can result in founder effects, increasing genetic differentiation between expanding populations and reducing genetic diversity along the expansion front. However, few studies have addressed these effects in long-distance migratory species, for which high dispersal ability might counter the effects of genetic drift. Monarchs (Danaus plexippus) are best known for undertaking a long-distance annual migration in North America, but have also dispersed around the world to form populations that do not migrate or travel only short distances. Here, we used microsatellite markers to assess genetic differentiation among 18 monarch populations and to determine worldwide colonization routes. Our results indicate that North American monarch populations connected by land show limited differentiation, probably because of the monarch's ability to migrate long distances. Conversely, we found high genetic differentiation between populations separated by large bodies of water. Moreover, we show evidence for serial founder effects across the Pacific, suggesting stepwise dispersal from a North American origin. These findings demonstrate that genetic drift played a major role in shaping allele frequencies and created genetic differentiation among newly formed populations. Thus, range expansion can give rise to genetic differentiation and declines in genetic diversity, even in highly mobile species.