scholarly journals Differences in Reproductive Potential of Two Populations of Catolaccus grandis (Hymenoptera: Pteromalidae) and Their Hybrids

2000 ◽  
Vol 83 (2) ◽  
pp. 137 ◽  
Author(s):  
Juan A. Morales-Ramos ◽  
M. Guadalupe Rojas ◽  
Edgar G. King
Keyword(s):  
Reproductive Potential ◽  
Catolaccus Grandis ◽  
Two Populations

scholarly journals Kin-Mediated Male Choice and Alternative Reproductive Tactics in Spider Mites

Biology ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 360
Author(s):  
Peter Schausberger ◽  
Yukie Sato
Keyword(s):  
Random Mating ◽  
Reproductive Potential ◽  
Spider Mites ◽  
Alternative Reproductive Tactics ◽  
Male Choice ◽  
Reproductive Tactics ◽  
Kin Competition ◽  
Context Specific ◽  
Two Populations

Optimal outbreeding and kin selection theories state that the degree of kinship is a fundamental determinant in any mating system. However, the role of kinship in male choice and alternative reproductive tactics (ARTs) is poorly known. We assessed the influence of kinship on male choice and expression of ARTs in two populations of two-spotted spider mites Tetranychus urticae. Male spider mites guard premature females, which is an indicator of mate choice, and may conditionally adopt fighting or sneaking tactics to secure access to females. Males competing with kin or non-kin were offered one kin or non-kin female (experiment 1) and single males were presented a choice of kin and non-kin females (experiment 2). Under kin competition, males of both populations were more prone to guard non-kin than kin females at a 3:1 fighter:sneaker ratio. Under non-kin competition, all males were fighters. Under no-choice, males used novelty as indicator of genetic dissimilarity, serving as absolute decision rule for outbreeding. Under choice, comparative evaluation allowed males to preferentially guard females with higher reproductive potential. Overall, our study suggests that male spider mites can assess kinship of rivals and prospective mates. Kin discrimination allows adaptive, context-specific non-random mating preference and adjustment of ARTs.

scholarly journals Adaptive phenotypic response to climate enabled by epigenetics in a K-strategy species, the fish Leucoraja ocellata (Rajidae)

2016 ◽  
Vol 3 (10) ◽  
pp. 160299 ◽  
Author(s):  
Jackie Lighten ◽  
Danny Incarnato ◽  
Ben J. Ward ◽  
Cock van Oosterhout ◽  
Ian Bradbury ◽  
...  
Keyword(s):  
Gene Expression ◽  
Large Population ◽  
Reproductive Potential ◽  
Future Climate Change ◽  
The Novel ◽  
Evolutionary Potential ◽  
Scotian Shelf ◽  
Evolutionary Time ◽  
Endemic Population ◽  
Two Populations

The relative importance of genetic versus epigenetic changes in adaptive evolution is a hotly debated topic, with studies showing that some species appear to be able to adapt rapidly without significant genetic change. Epigenetic mechanisms may be particularly important for the evolutionary potential of species with long maturation times and low reproductive potential (‘K-strategists’), particularly when faced with rapidly changing environmental conditions. Here we study the transcriptome of two populations of the winter skate ( Leucoraja ocellata ), a typical ‘K-strategist’, in Atlantic Canada; an endemic population in the southern Gulf of St Lawrence and a large population on the Scotian Shelf. The endemic population has been able to adapt to a 10°C higher water temperature over short evolutionary time (7000 years), dramatically reducing its body size (by 45%) significantly below the minimum maturation size of Scotian Shelf and other populations of winter skate, as well as exhibiting other adaptations in life history and physiology. We demonstrate that the adaptive response to selection has an epigenetic basis, cataloguing 3653 changes in gene expression that may have enabled this species to rapidly respond to the novel environment. We argue that the epigenetic augmentation of species evolutionary potential (its regulation though gene expression) can enable K-strategists to survive and adapt to different environments, and this mechanism may be particularly important for the persistence of sharks, skates and rays in the light of future climate change.

scholarly journals Influence of a cage farming on the population of the fish species Apareiodon affinis (Steindachner, 1879) in the Chavantes reservoir, Paranapanema River SP/PR, Brazil

2013 ◽  
Vol 24 (4) ◽  
pp. 438-448 ◽  
Author(s):  
Heleno Brandão ◽  
Javier Lobón-Cerviá ◽  
Igor Paiva Ramos ◽  
Ana Carolina Souto ◽  
André Batista Nobile ◽  
...  
Keyword(s):  
Condition Factor ◽  
Reproductive Potential ◽  
Fish Farming ◽  
Reproductive Period ◽  
Gonad Somatic Index ◽  
Biological Attributes ◽  
Net Cage ◽  
Net Cages ◽  
Two Populations ◽  
Somatic Index

AIM: The aim of the present study was to evaluate the diet and biological attributes of the population of Apareiodon affinis residing near net-cage fish farming activities in the Chavantes reservoir. METHODS: Samples were collected from two populations: one near the net cages (NC) and one from an area not influenced by these cages denominated the "reference site" (RS). Monthly sampling was carried out from Mar/2008 to Feb/2009. Fish were caught with a standardized effort using gill nets deployed for 14 hours. After all individuals were measured (standard length) and weighed (total weight, carcass weight , body weight without gonads). To determine the composition of the diet, the alimentary index was calculated (AI). We also calculated the length-weight relationship, condition factor, gonad-somatic index (GSI ) and reproductive potential. RESULTS: A total of 3050 individuals were caught. The results of the (AI) revealed that the item detritus was the main food used for populations of A. affinis studied in two areas (NC = 73.1% and RS = 95.7%). The use of feed on diet A. affinis was recorded for the populations of NC adding (20.5%) of the total items consumed by the population. The resident populations residing near net-cage showed higher condition factor and more reproductive period. CONCLUSIONS: The results show the ability of the species to benefit from the input of organic matter from fish farming activities, inserting a new item in their diet (ration). This work indicates that the species A. affinis managed to establish near net-cage, allocating enough energy to increase their reproductive period and maintain viable populations close to net-cage, evidenced by the high abundance. This study suggests that systems of fish farming in net-cage influence diet and biological attributes of the species A. affinis residents Chavantes reservoir, Brazil.

Comparison of Principal Component Solutions in Two Populations

Methodology ◽  
2016 ◽  
Vol 12 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Gregor Sočan
Keyword(s):  
Simulation Study ◽  
Principal Components ◽  
Common Factor ◽  
Principal Component ◽  
Component Model ◽  
Bootstrap Procedure ◽  
Factor Loadings ◽  
Component Loadings ◽  
Principal Component Model ◽  
Two Populations

Abstract. When principal component solutions are compared across two groups, a question arises whether the extracted components have the same interpretation in both populations. The problem can be approached by testing null hypotheses stating that the congruence coefficients between pairs of vectors of component loadings are equal to 1. Chan, Leung, Chan, Ho, and Yung (1999) proposed a bootstrap procedure for testing the hypothesis of perfect congruence between vectors of common factor loadings. We demonstrate that the procedure by Chan et al. is both theoretically and empirically inadequate for the application on principal components. We propose a modification of their procedure, which constructs the resampling space according to the characteristics of the principal component model. The results of a simulation study show satisfactory empirical properties of the modified procedure.

Molecular phylogeny and taxonomic evaluation of the genus Asaccus Dixon and Anderson, 1973 (Reptilia: Phyllodactylidae) in Iran

2020 ◽  
pp. 207-214
Author(s):  
Akbar Fattahi
Keyword(s):  
Molecular Phylogeny ◽  
Nuclear Gene ◽  
Genetic Distances ◽  
Genetic Lineage ◽  
New Taxon ◽  
Zagros Mountains ◽  
Relict Species ◽  
Taxonomical Revision ◽  
Two Populations ◽  
Taxonomic Evaluation

The Iranian species of the phyllodactylid geckos of the genus Asaccus are found only in the valleys of the Zagros Mountains, a region which represents an important area of endemism in western Iran. Recently, many relict species have been described from the central and southern parts of the Zagros Mountains, which were previously known as A. elisae. The recent descriptions of species within this complex suggest that diversity within the genus may be higher than expected and that its taxonomy and systematics should be revised. In the present study, phylogenetic relationships within the genus Asaccus were evaluated using two mitochondrial and one nuclear gene. Genetically, the genus shows high levels of variability. The molecular phylogeny of the genus suggests the presence of three main clades along the Zagros Mountains with the southern population (from the Hormozgan province) and one clade (A. sp8 and A. sp9) being sister taxon to A. montanus from UAE. The remaining samples are separated into two reciprocally monophyletic groups: the northern (Kurdistan, Kermanshah and Ilam provinces) and the central (Lorestan, Khuzestan, Kohgilouye-Bouyer Ahmad and Fars provinces) Zagros groups. The results of the present study suggest that populations attributed to A. elisae in Iran correspond to distinct lineages with high genetic distances. In brief, our results suggest that the genus needs a major taxonomical revision The Arabian origin of the genus has not been confirmed, because two populations from Zagros were located within the A. montanus, A. gallagheri and A. platyrhynchus clade. Further morphological analyses are needed to systematically define each genetic lineage as a new taxon.

Comparing Genetic Variation within Red Winter Wheat Populations with and without Image-Based Optical Sorter Selection

2019 ◽  
Vol 9 (2) ◽  
pp. 266-277
Author(s):  
Hussein M. Khaeim ◽  
Anthony Clark ◽  
Tom Pearson ◽  
Dr. David Van Sanford
Keyword(s):  
Genetic Variation ◽  
Fusarium Head Blight ◽  
Heading Date ◽  
Fusarium Head Blight Resistance ◽  
Gibberella Zeae ◽  
Mass Selection ◽  
Head Blight ◽  
Red Winter Wheat ◽  
Two Populations ◽  
Head Scab

Head scab is historically a devastating disease affecting not just all classes of wheat but also barley and other small grains around the world. Fusarium head blight (FHB), or head scab, is caused most often by Fusarium graminearum (Schwabe), (sexual stage – Gibberella zeae) although several Fusarium spp. can cause the disease. This study was conducted to determine the effect of mass selection for FHB resistance using an image-based optical sorter. lines were derived from the C0 and C2 of two populations to compare genetic variation within populations with and without sorter selection. Our overall hypothesis is that sorting grain results in improved Fusarium head blight resistance. Both of the used wheat derived line populations have genetic variation, and population 1 has more than population 17. They are significantly different from each other for fusarium damged kernel (FDK), deoxynivalenol (DON), and other FHB traits. Although both populations are suitable to be grown for bulks, population 1 seems better since it has more genetic variation as well as lower FDK and DON, and earlier heading date. Lines within each population were significantly different and some lines in each population had significantly lower FDK and DON after selection using an optical sorter. Some lines had significant reduction in both FDK and DON, and some others had either FDK or DON reduction. Lines of population 1 that had significant reduction, were more numerous than in population 17, and FDK and DON reduction were greater.

On the possibility of targeted prophylaxis of calcitriol-associated pregnancy complications at the preclinical stage

2020 ◽  
pp. 43-50
Author(s):  
N.V. Didenkul ◽  
Keyword(s):  
Vitamin D ◽  
Pregnancy Complications ◽  
Comparison Group ◽  
Reproductive Potential ◽  
Perinatal Outcomes ◽  
Fetal Distress ◽  
Optimal Level ◽  
Initial Study ◽  
Management Plan ◽  
Placental Dysfunction

According to recent studies, in the vitamin D deficiency state (VDD), pregnancy can be complicated and the optimal level of VD in the blood is one of the conditions for the realization of reproductive potential. The objective: the possibility to preventing calcitriol-associated pregnancy complications by the correcting VD deficiency at the preconception period. Materials and methods. 57 women with VDD were examined. A history of all women had a pregnancy complicated by placental dysfunction (PD); 27 of them were observed from the preconception period (main group – IA) and 30 – from the 1st trimester of pregnancy (comparison group – IB). The VD status by the blood level of the 25-hydroxyvitamin D by ELISA was determined. Women of both groups, in addition to the vitamin-mineral complex (VMC) were prescribed supplementation colecalciferol at a dose of 4.000 IU per day. Pregnant women of both groups received VMCs up to 16 weeks. After optimizing the level (3–4 months), women continued to take VD at a dose of 2.000 IU per day throughout pregnancy. Results. At the initial study, the VD level was 15.72±2.59 ng/ml in ІА and 16.1±1.99 ng/ml in ІВ group (U=883; p>0.05); after treatment increased to 38.31±3.29 ng/ml and 36.13±2.99 ng/ml (U=900; p>0.05). In group IA, the course of pregnancy was characterized by a lower frequency of complications: PD was diagnosed in 22.2% in group IA and 50% in group IB (F=0.0001; p<0.01); fetal distress in 3.7% and 10% (F=0.16; p<0.05): signs of amnionitis – in 18.5% and 33.3% (F=0.035; p<0.05); placental hypertrophy or hypotrophy – in 7.4% and 36.7% (F=0.00001; p<0.01), preeclampsia in 3.7% and 6.7% of women (F=0,54; p<0.05). The frequency of cesarean section in the comparison group was significantly higher (40% VS 25.9%, F=0.034; p<0.05). Conclusions. During pregnancy, which occurred in conditions of VDD, the frequency of some pregnancy complications, including preeclampsia, the threat of miscarriage, placental dysfunction was in 2–4 times higher than in women with optimized VD status. One of the directions of the individual management plan for women with a negative obstetric history can be the determination of the level of VD in the blood and correction of the VDD at the preconception period. This approach is a pathogenetically substantiated and promising direction for the prevention of some pregnancy complications and improvement of perinatal outcomes. Keywords: pregnancy, deficiency vitamin D, placental dysfunction, preconception period.

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