Major histocompatibility I gene diversity in the critically endangered Laysan duck (Anas laysanensis).

Quantifying the genetic composition of founder populations is important to the success of reintroduction programmes, especially for bottlenecked and/or specialized species, such as island endemics. By implementing admixture schemes based on genetic variability, captive breeding programmes can minimize the detrimental effects of bottlenecking, inbreeding depression, outbreeding depression, etc. Particular attention has been given to genes within the major histocompatibility complex (MHC) due to their direct correlation to an individual’s immunity. However, isolating and amplifying MHC haplotypes remains difficult owing to the high diversity and paralogous nature. We describe a method of MHC I haplotype isolation based on an iterative process of primer design for the endangered island endemic, the Laysan duck (Anas laysanensis). Ultimately, haplotype-specific primers allow for direct genotyping after gel electrophoresis based on the presence/absence of their respective amplicons. Using the developed techniques, a total of eight unique haplotypes were isolated and assayed across 21 Laysan duck individuals from Laysan Island (N = 10) and Midway Atoll (N = 11). The presence/absence of seven haplotypes were variable across individuals with three haplotypes present in 95% of individuals, three in 38% of individuals, and one in 90% of individuals. The protocols described herein provide a simple, cost-effective method for isolating haplotypes and monitoring existing MHC variation in Laysan ducks, and the general approach can be applied to other molecular markers and species with low genetic diversity.

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Cross-transferability-based identification and validation of simple sequence repeat (SSR) markers in oaks of western Himalayas

Silvae Genetica ◽

10.2478/sg-2021-0009 ◽

2021 ◽

Vol 70 (1) ◽

pp. 108-116

Author(s):

Chander Shekhar ◽

Anita Rawat ◽

Maneesh S. Bhandari ◽

Santan Barthwal ◽

Harish S. Ginwal ◽

...

Keyword(s):

Ssr Markers ◽

Gene Diversity ◽

Cost Effective ◽

Sequence Information ◽

Western Himalayas ◽

Population Genetic Analysis ◽

Expected Heterozygosity ◽

Cost Effective Method ◽

Quercus Semecarpifolia ◽

Simple Sequence

Abstract Cross-amplification is a cost-effective method to extend the applicability of SSR markers to closely related taxa which lack their own sequence information. In the present study, 35 SSR markers developed in four oak species of Europe, North America and Asia were selected and screened in five species of the western Himalayas. Fifteen markers were successfully amplified in Quercus semecarpifolia, followed by 11 each in Q. floribunda and Q. leucotrichophora, 10 in Q. glauca, and 9 in Q. lana-ta. Except two primer pairs in Q. semecarpifolia, all were found to be polymorphic. Most of the positively cross-amplified SSRs were derived from the Asian oak, Q. mongolica. The genoty-ping of 10 individuals of each species with positively cross-amplified SSRs displayed varied levels of polymorphism in the five target oak species, viz., QmC00419 was most polymorphic in Q. floribunda, QmC00716 in Q. glauca and Q. lanata, QmC01368 in Q. leucotrichophora, and QmC02269 in Q. semecarpifolia. Among five oak species, the highest gene diversity was depicted in Q. lanata and Q. semecarpifolia with expected heterozygosity (He = 0.72), while the minimum was recorded for Q. leucotrichophora and Q. glauca (He = 0.65). The SSRs validated here provide a valuable resource to carry out further population genetic analysis in oaks of the western Himalayas.

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Analysis of CMA-DAPI bands and preparation of fluorescent karyotypes in thirty Indian cultivars of Lens culinaris

Caryologia ◽

10.36253/caryologia-919 ◽

2021 ◽

Author(s):

Timir baran Jha ◽

Biplab Kumar Bhowmick ◽

Partha Roy

Keyword(s):

Cost Effective ◽

Fluorochrome Banding ◽

Banding Patterns ◽

Plant Chromosomes ◽

Cost Effective Method ◽

Production And Consumption ◽

Breeding Programmes ◽

Cultivated Species ◽

Protein Rich ◽

First Time

India holds a significant rank in production and consumption of the age old protein rich crop Lentil with only one cultivated species and a large number of phenotypically similar cultivars. The need for a reliable and cost effective method of genetic characterization to unravel differences within the Lentil cultivars was felt. The present paper adopted EMA based chromosome preparation followed by staining with two contrasting fluorochromes dyes CMA and DAPI that bind directly to GC and AT rich heterochromatic segments on chromosomes. Analysis of fluorochrome banding pattern furnished a comparative account of genetic diversity within the cultivars that could not be achieved by traditional karyotyping. The marker pair of nucleolar chromosomes (4th and 3rd, majorly) occupied a pivotal position to intensify differences between cultivars in terms of banding patterns around secondary constrictions, suggestive of yet unknown variation in heterochromatin composition. Our study has strengthened genetic background and relationships of Lentil cultivars. We observed certain types of unusual fluorochrome bands that put forward the exclusivity of Indian germplasm and have questioned the mainstream heterochromatin elements of plant chromosomes captured by CMA-DAPI stains. The comprehensive fluorescent karyotypes of 30 L. culinaris cultivars prepared for the first time, serve as an archetype for the benefit of future breeding programmes in any Indian crop.

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Genetic characterization of sunflower breeding resources from Argentina: assessing diversity in key open-pollinated and composite populations

Plant Genetic Resources ◽

10.1017/s1479262113000075 ◽

2013 ◽

Vol 11 (3) ◽

pp. 238-249 ◽

Cited By ~ 11

Author(s):

M. V. Moreno ◽

V. Nishinakamasu ◽

M. A. Loray ◽

D. Alvarez ◽

J. Gieco ◽

...

Keyword(s):

Molecular Characterization ◽

Phenotypic Diversity ◽

Gene Diversity ◽

Germplasm Collection ◽

Cost Effective ◽

Germplasm Collections ◽

Efficient Management ◽

Breeding Programmes ◽

Average Gene

Open-pollinated (OPs) and composite populations (CPs) represent a valuable resource for sunflower breeding programmes. However, little is known about the levels and distribution of genetic variation within each of these populations. In this study, quantitative and qualitative traits along with molecular markers were used to evaluate 14 populations from the Instituto Nacional de Tecnología Agropecuaria (INTA) sunflower germplasm collection. These populations were chosen to represent historically important accessions that still play a central role within the INTA sunflower breeding programme due to their extensive variation in diverse agronomically important traits. Nine quantitative and eight qualitative agro-morphological descriptors were recorded and compared with those of a larger set of accessions representative of the phenotypic diversity of the sunflower collection. Molecular characterization was conducted on a total of 311 individuals using 16 microsatellite markers. Overall, the average gene diversity was 0.56 and the average number of alleles per locus was 6.25. No statistically significant differences in genetic diversity were detected between the OPs and CPs. Global estimates ofFSTrevealed very high levels of differentiation among accessions (FST= 0.413,P< 0.05). Population structure analyses were consistent with the observed levels of differentiation and identified two major groups. The results of this work show that high global diversity is preserved within the accessions analysed here. Additionally, this study provides a set of reliable and discriminant markers for the cost-effective molecular characterization of sunflower accessions, along with the guidelines for the delineation of sampling strategies for OPs and CPs, thus aiding the efficient management and exploitation of sunflower germplasm collections.

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High MHC gene copy number maintains diversity despite homozygosity in a Critically Endangered single-island endemic bird, but no evidence of MHC-based mate choice

10.1101/2020.02.03.932590 ◽

2020 ◽

Cited By ~ 1

Author(s):

Martin Stervander ◽

Elisa G. Dierickx ◽

Jack Thorley ◽

M. de L. Brooke ◽

Helena Westerdahl

Keyword(s):

Mate Choice ◽

Gene Diversity ◽

Gene Copy Number ◽

Small Population ◽

Critically Endangered ◽

Gene Copy ◽

Immune Gene ◽

Class I Mhc ◽

Mhc I ◽

Island Endemic

AbstractSmall population sizes can, over time, put species at risk due to the loss of genetic variation and the deleterious effects of inbreeding. Losing diversity in the major histocompatibility complex (MHC) could be particularly harmful, given its key role in the immune system. Here, we assess MHC class I (MHC-I) diversity and its effects on mate choice and survival in the Critically Endangered Raso lark Alauda razae, a species restricted to the 7 km2 islet of Raso (Cape Verde) since ~1460, whose population size has dropped as low as 20 pairs. Exhaustively genotyping 122 individuals, we find no effect of MHC-I genotype/diversity on mate choice or survival. However, we demonstrate that MHC-I diversity has been maintained through extreme bottlenecks by retention of a high number of gene copies (at least 14), aided by co-segregation of multiple haplotypes comprising 2–8 linked MHC-I loci. Within-locus homozygosity is high, contributing to comparably low population-wide diversity. Conversely, each individual had comparably many alleles, 6–16 (average 11), and the large and divergent haplotypes occur at high frequency in the population, resulting in high within-individual MHC-I diversity. This functional immune gene diversity will be of critical importance for this highly threatened species’ adaptive potential.

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Lessons from the Looming Extinction of the Tasmanian Devil

Pacific Conservation Biology ◽

10.1071/pc080151 ◽

2008 ◽

Vol 14 (3) ◽

pp. 151 ◽

Cited By ~ 3

Author(s):

D. Lunney ◽

M. Jones ◽

H. McCullum

Keyword(s):

Cancer Cells ◽

Captive Breeding ◽

Active Management ◽

Tasmanian Devil ◽

Population Bottlenecks ◽

Low Genetic Diversity ◽

Devil Facial Tumour Disease ◽

In The Wild ◽

Breeding Programmes ◽

Infectious Cancer

Extinction in the wild is now regarded as likely for the Tasmanian Devil Sarcophilus harrissi. In 1996, a disease, Devil Facial Tumour Disease (DFTD), was seen in a Devil in the wild. By mid-2008, the population had declined by about 70%, and the disease was spreading rapidly from east to west across Tasmania. DFTD is an infectious cancer, passed from one Devil to another principally, or entirely, by biting. The bite implants the cancer cells; the low genetic diversity in the Tasmanian Devil population from previous population bottlenecks or selective sweeps means that those cancer cells are not recognized by the immune system and the cancer grows in the infected Devil. Estimates of the time to extinction in the wild range from about 20 to 35 years. If, however, there are resistant genotypes within the Devil population then extinction in the wild may be averted, with numbers augmented through captive breeding programmes and active management to spread these genotypes in the wild.

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Using off – set handpumps — a cost-effective method to protect drinking water in rural villages

Waterlines ◽

10.3362/0262-8104.1984.019 ◽

1984 ◽

Vol 2 (4) ◽

pp. 25-26

Author(s):

Daniel Jenkins

Keyword(s):

Drinking Water ◽

Cost Effective ◽

Rural Villages ◽

Cost Effective Method

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CAD Of Anticorrosive Protection Of Steel Structures

Promyshlennoe i Grazhdanskoe Stroitel stvo ◽

10.33622/0869-7019.2019.09.18-23 ◽

2019 ◽

pp. 18-23

Keyword(s):

Protective Coating ◽

Computer Aided Design ◽

Steel Structures ◽

Cost Effective ◽

Operating Conditions ◽

Computational Tool ◽

Protection Method ◽

Cost Effective Method ◽

The Cost ◽

Aided Design

The choice of cost-effective method of anticorrosive protection of steel structures is an urgent and time consuming task, considering the significant number of protection ways, differing from each other in the complex of technological, physical, chemical and economic characteristics. To reduce the complexity of solving this problem, the author proposes a computational tool that can be considered as a subsystem of computer-aided design and used at the stage of variant and detailed design of steel structures. As a criterion of the effectiveness of the anti-corrosion protection method, the cost of the protective coating during the service life is accepted. The analysis of existing methods of steel protection against corrosion is performed, the possibility of their use for the protection of the most common steel structures is established, as well as the estimated period of effective operation of the coating. The developed computational tool makes it possible to choose the best method of protection of steel structures against corrosion, taking into account the operating conditions of the protected structure and the possibility of using a protective coating.

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Monitoring effluent quality in hypertrophic wastewater reservoirs using remote sensing

Water Science & Technology ◽

10.2166/wst.1996.0148 ◽

1996 ◽

Vol 33 (8) ◽

pp. 23-29 ◽

Cited By ~ 3

Author(s):

I. Dor ◽

N. Ben-Yosef

Keyword(s):

Water Quality ◽

Theoretical Model ◽

Principal Component ◽

Cost Effective ◽

Operational Parameters ◽

Effluent Quality ◽

Optical Images ◽

Routine Monitoring ◽

Cost Effective Method ◽

Wastewater Quality

About one hundred and fifty wastewater reservoirs store effluents for irrigation in Israel. Effluent qualities differ according to the inflowing wastewater quality, the degree of pretreatment and the operational parameters. Certain aspects of water quality like concentration of organic matter, suspended solids and chlorophyll are significantly correlated with the water column transparency and colour. Accordingly optical images of the reservoirs obtained from the SPOT satellite demonstrate pronounced differences correlated with the water quality. The analysis of satellite multispectral images is based on a theoretical model. The model calculates, using the radiation transfer equation, the volume reflectance of the water body. Satellite images of 99 reservoirs were analyzed in the chromacity space in order to classify them according to water quality. Principal Component Analysis backed by the theoretical model increases the method sensitivity. Further elaboration of this approach will lead to the establishment of a time and cost effective method for the routine monitoring of these hypertrophic wastewater reservoirs.

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