The biochemical genetics of an island population of the house mouse

1970 ◽  
Vol 176 (1042) ◽  
pp. 87-103 ◽  
Keyword(s):  
Natural Selection ◽  
Early Spring ◽  
The Other ◽  
Island Population ◽  
Starch Gel Electrophoresis ◽  
Allele Distribution ◽  
Juvenile Mortality ◽  
Genotype Frequencies ◽  
Hardy Weinberg Equilibrium ◽  
Time Of Year

House mice have been isolated on the small Welsh island of Skokholm since the 1890s, when the island was colonized by a few animals inadvertently brought over from the nearby mainland in sacks. This paper describes a study (by starch gel electrophoresis) of variants at six gene loci in samples from the island population collected at the beginning and end of breeding in two consecutive years. Four mainland mouse populations were sampled for comparison. The Skokholm mice were polymorphic at all six loci, and were segregating for fourteen of the fifteen alleles found in the mainland samples. Three of the six loci on Skokholm indicated the action of natural selection: two showed an increase over the number of heterozygotes expected on the Hardy–Weinberg equilibrium during one season (winter in one case, summer in the other) and a decrease in this excess at another time of year, while the third showed directed selection against mice carrying a particular allele. These changes in allele and genotype frequencies occurred during the first year of the study and were repeated in the second year. Variants at the other three loci indicated the influence of the social structure of the mice on allele distribution, showing that the population was not behaving as a panmictic unit. These results have to be interpreted in terms of the ecology and population dynamics of the island mice. The population size varies considerably: during the winter there is no successful breeding and a mortality of 50 to 90 %, the number dying depending on the mean temperature in early spring; in the summer the population increases tenfold (much less than the increase predicted from knowledge of litter sizes and breeding rates: there must be considerable juvenile mortality). Despite the poverty of genic variation that must have existed in the early stages of colonization on Skokholm, natural selection has acted to increase the variation to a level not very different from that on the mainland.

scholarly journals Genetic analysis of pharmacogenomic VIP variants in the Wa population from Yunnan Province of China

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Dandan Li ◽  
Linna Peng ◽  
Shishi Xing ◽  
Chunjuan He ◽  
Tianbo Jin
Keyword(s):  
Ethnic Group ◽  
Theoretical Basis ◽  
Yunnan Province ◽  
Drug Response ◽  
The Other ◽  
Allele Distribution ◽  
Genotype Frequencies ◽  
Study Results ◽  
Significant Difference ◽  
The Future

Abstract Background The variation of drug responses and target does among individuals is mostly determined by genes. With the development of pharmacogenetics and pharmacogenomics, the differences in drug response between different races seem to be mainly caused by the genetic diversity of pharmacodynamics and pharmacokinetics genes. Very important pharmacogenetic (VIP) variants mean that genes or variants play important and vital roles in drug response, which have been listed in pharmacogenomics databases, such as Pharmacogenomics Knowledge Base (PharmGKB). The information of Chinese ethnic minorities such as the Wa ethnic group is scarce. This study aimed to uncover the significantly different loci in the Wa population in Yunnan Province of China from the perspective of pharmacogenomics, to provide a theoretical basis for the future medication guidance, and to ultimately achieve the best treatment in the future. Results In this study, we recruited 200 unrelated healthy Wa adults from the Yunnan province of China, selected 52 VIP variants from the PharmGKB for genotyping. We also compared the genotype frequency and allele distribution of VIP variants between Wa population and the other 26 populations from the 1000 Genomes Project (http://www.1000Genomes.org/). Next, χ2 test was used to determine the significant points between these populations. The study results showed that compared with the other 26 population groups, five variants rs776746 (CYP3A5), rs4291 (ACE), rs3093105 (CYP4F2), rs1051298 (SLC19A1), and rs1065852 (CYP2D6) had higher frequencies in the Wa population. The genotype frequencies rs4291-TA, rs3093105-CA, rs1051298-AG and rs1065852-GA were higher than those of the other populations, and the allele distributions of rs4291-T and rs3093105-C were significantly different. Additionally, the difference between the Wa ethnic group and East Asian populations, such as CDX, CHB, and CHS, was the smallest. Conclusions Our research results show that there is a significant difference in the distribution of VIP variants between the Wa ethnic group and the other 26 populations. The study results will have an effect on supplementing the pharmacogenomics information for the Wa population and providing a theoretical basis for individualised medication for the Wa population.

Genetic Characterization of Indigenous Duck of North-East Region using Microsatellite Markers

2021 ◽  
Author(s):  
Purabi Kaushik ◽  
Jnyanashree Saikia ◽  
Kabitabala Kalita ◽  
Rajjyoti Deka ◽  
J. Saharia
Keyword(s):  
Microsatellite Markers ◽  
Genetic Characterization ◽  
The Other ◽  
North East India ◽  
North East ◽  
Brahmaputra Valley ◽  
East Region ◽  
Hardy Weinberg Equilibrium ◽  
Common Variety

Background: Duck farming plays a significant role, next to chicken in the socio-economic uplift men of the rural farmers of North-East India. Pati duck is the most common duck breed in the Brahmaputra valley of Assam and the other common variety reared in North-East India is Chara-Chambeli, however it originatein Kerala. Genetic characterization plays a significant role for formulation of breeding strategies for improvement of any breed. Microsatellites are codominant in nature and are highly polymorphic. High level of allelic variation, co-dominant mode of inheritance and potential for automated analysis make them an excellent tool for genotyping, mapping and genetic characterization. Pati duck is the most common duck breed in the Brahmaputra valley of Assam and the other common variety reared in North-East India is Chara-Chambeli however its origin in Kerela. Therefore, the present investigation was carried out to characterize these two duck breeds using microsatellite markers to evaluate the genetic diversity in these two duck population. Methods: For the present study, Blood sample were collected from 50 Patiducks and 50 Chara-Chambeli ducks from different parts of North-East India. Assessment of genetic characterization of duck breeds of north-east region were carried out using 16 microsatellite markers and population genetics analysis were done by POPGENE software. Result: In the present study, all the studied loci were highly polymorphic. Analysis generated a total of 41 microsatellite alleles. The number of observed alleles (Na) with an overall mean of 1.93±0.258. However, the effective number of alleles (Ne) with a mean of 1.6933±0.2712. The Shannon’s information index was found to a mean value of 0.5685±0.1693. The overall means for observed (HO) and expected (He) heterozygosities were 0.2889±0.2477 and 0.5289±0.0853, respectively. The chi-square (χ2) test for Hardy-Weinberg equilibrium revealed that all the loci are in within Hardy-Weinberg equilibrium.

scholarly journals Genetic polymorphism of milk protein loci in Argentinian Holstein cattle

2000 ◽  
Vol 23 (4) ◽  
pp. 819-823 ◽  
Author(s):  
Adriana Gloria Bonvillani ◽  
Miguel Angel Di Renzo ◽  
Iván Nicolás Tiranti
Keyword(s):  
Genetic Polymorphism ◽  
Milk Protein ◽  
Genotypic Diversity ◽  
Genetic Distances ◽  
Holstein Cattle ◽  
Starch Gel Electrophoresis ◽  
Beta Casein ◽  
Hardy Weinberg Equilibrium ◽  
Quality Of Milk ◽  
Beta Lactoglobulin

Some alleles of milk protein loci are associated with superior cheese production characteristics. The genetic polymorphism of the milk protein loci alphas1-casein, beta-casein, k-casein and beta-lactoglobulin was examined in Argentinian Holstein cattle. Samples from 12 herds of four regions of Córdoba were analyzed by starch gel electrophoresis. The chi² test was used to assess whether the populations were in Hardy-Weinberg equilibrium. Genotypic diversity was analyzed by the Shannon-Weaver index. The observed genotypic frequencies were analyzed by Hedrick's genetic identity and the genetic distance of Balakrishnan and Sanghvi. The allelic and genotypic frequencies were similar to those of other Holstein populations. The genotypic frequencies of the alphas1-casein and beta-casein loci were in equilibrium, whereas in some populations the k-casein and beta-lactoglobulin loci were not. According to the Shannon-Weaver index the total genetic diversity within each herd was greater than 96%. The high values of identity agreed with the low genetic distances among populations. We conclude that there is extensive genetic homogeneity in Holstein cattle in Córdoba Province and that it would be feasible to select for B alleles at the k-casein and b-lactoglobulin loci in order to improve the quality of milk available for cheese manufacturing.

scholarly journals Evaluation of the performance of three advisory methods for nitrogen fertilization of sugar beet and potatoes.

1989 ◽  
Vol 37 (2) ◽  
pp. 143-155 ◽  
Author(s):  
J.J. Neeteson
Keyword(s):  
Crop Yields ◽  
Current Method ◽  
Early Spring ◽  
The Other ◽  
Fertilizer N ◽  
Potato Tubers ◽  
Current Recommendation ◽  
Mineral N ◽  
Fertilizer Recommendation ◽  
The Difference

The performances of 3 different N fertilizer recommendation methods were retrospectively tested with data obtained from 150 trials with sugarbeet and 98 trials with potatoes in the Netherlands in 1973-82. The recommendations consisted of applying a fixed N rate in all situations (126 kg N/ha for sugarbeet and 286 kg N/ha for potatoes), the current Dutch method, which takes only the amount of mineral N present in the soil in early spring into account, and a refinement of the current method, which also takes soil type and recent applications of organic manures into account. On av., significantly lower amounts of fertilizer N were recommended with the current method. The difference from the other methods was on av. 25 kg N/ha for sugarbeet and 30 kg N/ha for potatoes. With the refined current method the highest crop yields were obtained but the difference from the other methods was not significant and averaged only 0.3-0.4 t/ha for sugarbeet and 0.1-0.2 t/ha for potatoes. The recovery of fertilizer N by the potato tubers was 2% higher with the current method than with the other methods. Based on these findings it is concluded that the current recommendation method is preferable to the other methods. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Fish nursery value of algae habitats in temperate coastal reefs

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6797 ◽  
Author(s):  
Hilmar Hinz ◽  
Olga Reñones ◽  
Adam Gouraguine ◽  
Andrew F. Johnson ◽  
Joan Moranta
Keyword(s):  
Juvenile Fish ◽  
Strong Association ◽  
Late Summer ◽  
Early Spring ◽  
Rocky Reef ◽  
Term Survival ◽  
Fish Nursery ◽  
Prey Biomass ◽  
Reduced Height ◽  
Time Of Year

The nursery function of coastal habitats is one of the most frequently mentioned and recognized ecosystem services in the valuation of coastal ecosystems. Despite its importance our understanding of the precise habitat parameters and mechanisms that make a habitat important as a nursery area is still limited for many species. The study aimed to establish the importance of different algae morphotypes in providing shelter and food for juvenile coastal fish during the main settlement peaks, in early spring and late summer, in littoral rocky reef systems in the Northwestern Mediterranean. The results of our study showed strong seasonal differences in algae cover, composition and height between the two sampling periods. Overall, during spring the algae were well developed, while in late summer, both density and height, of most algae decreased considerably. Equally, prey biomass, in form of suitable sized invertebrate fauna associated to the algae, decreased. Accordingly, the shelter and food for the fish settling in this habitat during late summer were less abundant, indicating a mismatch between the observed presence of juvenile fish and optimal habitat conditions. Differences in prey densities were detected between algae morphotypes, with structurally more complex algae, such as Cystoseira spp. and Halopteris spp. consistently containing more prey, independent of season, compared to simpler structured morphotypes such as Dictoytales. The study furthermore related juvenile fish density to habitats dominated by different algae morphotypes. Out of the three-study species (Diplodus vulgaris, Symphodus ocellatus, Coris julis) only S. ocellatus showed a significant association with an algae habitat. S. ocellatus related positively to habitats dominated by Dictoytales which provided the highest cover during late summer but had the lowest prey densities. A strong association of this species with Cystoseira, as reported by other studies, could not be confirmed. Cystoseira was abundant within the study area but in a state of dieback, showing loss and reduced height of foliage, typical for the time of year within the study area. It is therefore likely that algae-fish associations are context-dependent and that several algae species may fulfil similar functions. We also discovered that prey biomass did not appear to have an important effect on juvenile abundances. Nevertheless, the availability of prey may influence juvenile fish condition, growth performance and ultimately long-term survival. We therefore suggest that future studies on habitat quality should also include, besides abundance, indicators related to the condition and growth of juveniles.

scholarly journals Flight period of some parasitoids and a predator of the olive black scale (Saissetia oleae Olivier) on Corfu island

2017 ◽  
Vol 5 ◽  
pp. 43 ◽  
Author(s):  
Μ. V. Macropodi
Keyword(s):  
Natural Enemies ◽  
The Other ◽  
Flight Period ◽  
Chilocorus Bipustulatus ◽  
Black Scale ◽  
Saissetia Oleae ◽  
Time Of Year

The time of year the adults (flight period) of the parasitoids of S. oleae: Μetaphycus helvolus, Μetaphycus lounsburyi, Scutelista cyanea and Moranila californica and the predator Chilocorus bipustulatus are present, was determined in three areas of Corfu island: Lima, Kontocali and Avliotes. M. helvolus apparently has two flight periods: the first is from A­pril till July and the second from November till December. All the other natural enemies have only one flight period per year. The flight period of M. lounsburyi is from April till August, while S. cyanea flies from August till the end of September or the first days of Oc­tober, and M. californica adults are present from July till the middle of December. Adults of C. bipustulatus appeared from July till December or the middle of January.

scholarly journals ECONOMICS OF NITROGEN USE IN DAIRYING

1982 ◽  
pp. 70-75
Author(s):  
D.A.L. Buxton
Keyword(s):  
New Zealand ◽  
Research Work ◽  
Dairy Farms ◽  
Early Spring ◽  
The Other ◽  
Stocking Rate ◽  
Nitrogen Use

During the last 10 to 15 years, the use of fertiliser N at low rates on New Zealand dairy farms has become more popular. There are many ways in which fertiliser N can be used to increase pasture and milkfat production. Five of those options are analysed, viz. I. High rates of N. 2. Bridging a spring feed deficit. 3. Increasing stocking rate. 4. Earlier calving. 5. More cow condition. Research work is finding the best times and rates of application of N. The extra pasture produced must then be utilised to maximise milkfat responses. Trials have shown that the use of high rates of fertiliser N ( > 80 kg N/ha) is unlikely to be profitable on N.Z. dairy farms. N used to enable more cows to be wintered, and then milked in early spring, appears to be very profitable, due to better utilisation of later spring-autumn pasture growth. The other three options are also profitable, but the increase in total farm milkfat production is only 3 to 4%. The options need to be tested more thoroughly with models and grazing experiments.

Identification of Australian barley cultivars by laboratory methods: gel electrophoresis and gel isoelectric focusing of the endosperm proteins

1977 ◽  
Vol 17 (89) ◽  
pp. 1020 ◽  
Author(s):  
J McCausland ◽  
CW Wrigley
Keyword(s):  
Isoelectric Focusing ◽  
Gel Electrophoresis ◽  
Water Soluble ◽  
The Other ◽  
Starch Gel Electrophoresis ◽  
Laboratory Methods ◽  
Barley Cultivars ◽  
Starch Gel ◽  
Electrophoretic Techniques ◽  
Gel Isoelectric Focusing

A range of laboratory methods was examined for their ability to distinguish between 19 barley cultivars currently grown in Australia. Aleurone colour, revealed after mechanical or chemical dehulling, differentiated Abyssinian, Atlas, Cape and Corvette from the other cultivars. Peroxidase and phenol testing were not useful. Seven different patterns were obtained for the hordeins of lowest mobility by starch gel electrophoresis. Further distinction was provided by flat gel isoelectric focusing of the water-soluble and hordein proteins for which 13 different pattern-groupings were obtained. The two electrophoretic techniques complemented one another, so that the use of both methods left only a few cultivars that could not be distinguished.

“Data for the Problem of Evolution in Man. V. On the Correlation between Duration of Life and the Number of Offspring”

1901 ◽  
Vol 35 (6) ◽  
pp. 458-479
Author(s):  
M. Beeton ◽  
G. U. Yule ◽  
Karl Pearson
Keyword(s):  
Natural Selection ◽  
Breeding Season ◽  
The Other ◽  
Similar Statement ◽  
Men And Women ◽  
Darwinian Theory ◽  
Theory Of Evolution ◽  
Biennial Plants ◽  
Long Life ◽  
Breeding Seasons

According to the Darwinian theory of evolution the members of a community less fitted to their environment are removed by death. But this process of natural selection would not permanently modify a race, if the members thus removed were able before death to propagate their species in average numbers. It then becomes an important question to ascertain how far duration of life is related to fertility. In the case of many insects death can interfere only with their single chance of offspring; they live or not for their one breeding season only. A similar statement holds good with regard to annual and biennial plants. In such cases there might still be a correlation between duration of life and fertility, but it would be of the indirect character, which we actually find in the case of men and women living beyond sixty years of age—a long life means better physique and better physique increased fertility. On the other hand, there is a direct correlation of fertility and duration of life in the case of those animals which generally survive a number of breeding seasons, and it is this correlation which we had at first in view when investigating the influence of duration of life on fertility in man. The discovery of the indirect factor in the correlation referred to above was therefore a point of much interest. For it seems to show that the physique fittest to survive is really the physique which is in itself (and independently of the duration of life) most fecund.

Solving Hardy-Weinberg with Geometry: An Integration of Biology and Math

2017 ◽  
Vol 79 (4) ◽  
pp. 309-312
Author(s):  
Laura A. Schoenle ◽  
Matthew Thomas
Keyword(s):  
Scientific Theory ◽  
Geometric Interpretation ◽  
Student Understanding ◽  
Weinberg Equilibrium ◽  
The Core ◽  
Distributive Property ◽  
Genotype Frequencies ◽  
Hardy Weinberg Equilibrium ◽  
Using Data ◽  
And Mathematics

Introducing Hardy-Weinberg equilibrium into the high school or college classroom can be difficult because many students struggle with the mathematical formalism of the Hardy-Weinberg equations. Despite the potential difficulties, incorporating Hardy-Weinberg into the curriculum can provide students with the opportunity to investigate a scientific theory using data and integrate across the disciplines of biology and mathematics. We present a geometric way to interpret and visualize Hardy-Weinberg equilibrium, allowing students to focus on the core ideas without algebraic baggage. We also introduce interactive applets that draw on the distributive property of mathematics to allow students to experiment in real time. With the applets, students can observe the effects of changing allele frequencies on genotype frequencies in a population at Hardy-Weinberg equilibrium. Anecdotally, we found use of the geometric interpretation led to deeper student understanding of the concepts and improved the students' ability to solve Hardy-Weinberg-related problems. Students can use the ideas and tools provided here to draw connections between the biology and mathematics, as well as between algebra and geometry.

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