Changes in the amount of kidney pigmented macrophage aggregates throughout the breeding cycle of female Ohrid trout, Salmo letnica Kar. (Teleostei, Salmonidae)

2011 ◽  
Vol 75 (2) ◽  
pp. 176-181 ◽  
Author(s):  
Maja Jordanova ◽  
Maria João Rocha ◽  
Katerina Rebok ◽  
Eduardo Rocha
Keyword(s):  
Breeding Cycle ◽  
Macrophage Aggregates

SEM and TEM observations of sperm development in the testis of the freshwater fish Oreochromis mossambicus

1990 ◽  
Vol 48 (3) ◽  
pp. 58-59
Author(s):  
Daryl A. Cornish ◽  
George L. Smit
Keyword(s):  
Morphological Characteristics ◽  
Oreochromis Mossambicus ◽  
Breeding Cycle ◽  
Limited Information ◽  
North West ◽  
The North ◽  
Sem And Tem ◽  
Sperm Development ◽  
Ultrastructural Characteristics ◽  
The University

Oreochromis mossambicus is currently receiving much attention as a candidater species for aquaculture programs within Southern Africa. This has stimulated interest in its breeding cycle as well as the morphological characteristics of the gonads. Limited information is available on SEM and TEM observations of the male gonads. It is known that the testis of O. mossambicus is a paired, intra-abdominal structure of the lobular type, although further details of its characteristics are not known. Current investigations have shown that spermatids reach full maturity some two months after the female becomes gravid. Throughout the year, the testes contain spermatids at various stages of development although spermiogenesis appears to be maximal during November when spawning occurs. This paper describes the morphological and ultrastructural characteristics of the testes and spermatids.Specimens of this fish were collected at Syferkuil Dam, 8 km north- west of the University of the North over a twelve month period, sacrificed and the testes excised.

scholarly journals Increasing selection gain and accuracy of harvest prediction models in Jatropha through genome-wide selection

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adriano dos Santos ◽  
Erina Vitório Rodrigues ◽  
Bruno Galvêas Laviola ◽  
Larissa Pereira Ribeiro Teodoro ◽  
Paulo Eduardo Teodoro ◽  
...  
Keyword(s):  
Prediction Models ◽  
Block Design ◽  
Phenotypic Selection ◽  
Breeding Population ◽  
Breeding Cycle ◽  
Selection Cycle ◽  
Genome Wide ◽  
Random Block ◽  
Random Block Design ◽  
Number Of Individuals

AbstractGenome-wide selection (GWS) has been becoming an essential tool in the genetic breeding of long-life species, as it increases the gain per time unit. This study had a hypothesis that GWS is a tool that can decrease the breeding cycle in Jatropha. Our objective was to compare GWS with phenotypic selection in terms of accuracy and efficiency over three harvests. Models were developed throughout the harvests to evaluate their applicability in predicting genetic values in later harvests. For this purpose, 386 individuals of the breeding population obtained from crossings between 42 parents were evaluated. The population was evaluated in random block design, with six replicates over three harvests. The genetic effects of markers were predicted in the population using 811 SNP's markers with call rate = 95% and minor allele frequency (MAF) > 4%. GWS enables gains of 108 to 346% over the phenotypic selection, with a 50% reduction in the selection cycle. This technique has potential for the Jatropha breeding since it allows the accurate obtaining of GEBV and higher efficiency compared to the phenotypic selection by reducing the time necessary to complete the selection cycle. In order to apply GWS in the first harvests, a large number of individuals in the breeding population are needed. In the case of few individuals in the population, it is recommended to perform a larger number of harvests.

scholarly journals The Bdkrb2 gene family provides a novel view of viviparity adaptation in Sebastes schlegelii

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jingjing Niu ◽  
Weihao Song ◽  
Rui Li ◽  
Haiyang Yu ◽  
Jian Guan ◽  
...  
Keyword(s):  
Protein Structure ◽  
Vascular System ◽  
Critical Role ◽  
Future Research ◽  
Breeding Cycle ◽  
Exterior Surface ◽  
Black Rockfish ◽  
Vascular Regulation ◽  
Sebastes Schlegelii ◽  
Ovarian Wall

Abstract Background Black rockfish (Sebastes schlegelii) is a viviparous teleost. We proposed that the rockfish ovarian wall had a similar function to the uterus of mammals previously. In the present study, the well-developed vascular system was observed in the ovarian wall and the exterior surface of the egg membrane. In gestation, adaptation of the ovary vasculature to the rising needs of the embryos occurs through both vasodilation and neovascularization. Bdkrb2, encoding a receptor for bradykinin, plays a critical role in the control of vasodilatation by regulating nitric oxide production. Results Eight Bdkrb2 genes were identified in the black rockfish genome. These genes were located on chromosome 14, which are arranged in a tandem array, forming a gene cluster spanning 50 kb. Protein structure prediction, phylogenetic analysis, and transcriptome analysis showed that eight Bdkrb2 genes evolved two kinds of protein structure and three types of tissue expression pattern. Overexpression of two Bdkrb2 genes in zebrafish indicated a role of them in blood vessel formation or remodeling, which is an important procedure for the viviparous rockfish getting prepared for fertilization and embryos implantation. Conclusions Our study characterizes eight Bdrkb2 genes in the black rockfish, which may contribute to preparation for fertilization and embryo implantation. This research provides a novel view of viviparity adaptation and lays the groundwork for future research into vascular regulation of ovarian tissue in the breeding cycle in black rockfish.

scholarly journals Genomics and breeding innovations for enhancing genetic gain for climate resilience and nutrition traits

2021 ◽  
Author(s):  
Pallavi Sinha ◽  
Vikas K. Singh ◽  
Abhishek Bohra ◽  
Arvind Kumar ◽  
Jochen C. Reif ◽  
...  
Keyword(s):  
Statistical Methods ◽  
Genetic Gain ◽  
Crop Improvement ◽  
Breeding Population ◽  
Breeding Cycle ◽  
Climate Resilience ◽  
Heritability Estimation ◽  
Improvement Programs ◽  
Statistical Designs ◽  
Novel Alleles

Abstract Key message Integrating genomics technologies and breeding methods to tweak core parameters of the breeder’s equation could accelerate delivery of climate-resilient and nutrient rich crops for future food security. Abstract Accelerating genetic gain in crop improvement programs with respect to climate resilience and nutrition traits, and the realization of the improved gain in farmers’ fields require integration of several approaches. This article focuses on innovative approaches to address core components of the breeder’s equation. A prerequisite to enhancing genetic variance (σ2g) is the identification or creation of favorable alleles/haplotypes and their deployment for improving key traits. Novel alleles for new and existing target traits need to be accessed and added to the breeding population while maintaining genetic diversity. Selection intensity (i) in the breeding program can be improved by testing a larger population size, enabled by the statistical designs with minimal replications and high-throughput phenotyping. Selection priorities and criteria to select appropriate portion of the population too assume an important role. The most important component of breeder′s equation is heritability (h2). Heritability estimates depend on several factors including the size and the type of population and the statistical methods. The present article starts with a brief discussion on the potential ways to enhance σ2g in the population. We highlight statistical methods and experimental designs that could improve trait heritability estimation. We also offer a perspective on reducing the breeding cycle time (t), which could be achieved through the selection of appropriate parents, optimizing the breeding scheme, rapid fixation of target alleles, and combining speed breeding with breeding programs to optimize trials for release. Finally, we summarize knowledge from multiple disciplines for enhancing genetic gains for climate resilience and nutritional traits.

scholarly journals Breeding of High Cooking and Eating Quality in Rice by Marker-Assisted Backcrossing (MABc) Using KASP Markers

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 804
Author(s):  
Me-Sun Kim ◽  
Ju-Young Yang ◽  
Ju-Kyung Yu ◽  
Yi Lee ◽  
Yong-Jin Park ◽  
...  
Keyword(s):  
Genetic Background ◽  
Amylose Content ◽  
Yield Potential ◽  
Eating Quality ◽  
Breeding Cycle ◽  
Recurrent Parent ◽  
Rice Varieties ◽  
Breeding Programs ◽  
Genome Wide ◽  
Cooking And Eating Quality

The primary goals of rice breeding programs are grain quality and yield potential improvement. With the high demand for rice varieties of premium cooking and eating quality, we developed low-amylose content breeding lines crossed with Samgwang and Milkyqueen through the marker-assisted backcross (MABc) breeding program. Trait markers of the SSIIIa gene referring to low-amylose content were identified through an SNP mapping activity, and the markers were applied to select favorable lines for a foreground selection. To rapidly recover the genetic background of Samgwang (recurrent parent genome, RPG), 386 genome-wide markers were used to select BC1F1 and BC2F1 individuals. Seven BC2F1 lines with targeted traits were selected, and the genetic background recovery range varied within 97.4–99.1% of RPG. The amylose content of the selected BC2F2 grains ranged from 12.4–16.8%. We demonstrated the MABc using a trait and genome-wide markers, allowing us to efficiently select lines of a target trait and reduce the breeding cycle effectively. In addition, the BC2F2 lines confirmed by molecular markers in this study can be utilized as parental lines for subsequent breeding programs of high-quality rice for cooking and eating.

A test of the predator avoidance hypothesis to explain delayed onset of communal breeding

2019 ◽  
Vol 97 (4) ◽  
pp. 332-339
Author(s):  
D. Strickland ◽  
E. Brouwer ◽  
T.M. Burg
Keyword(s):  
Predator Avoidance ◽  
Group Living ◽  
Breeding Cycle ◽  
Communal Breeding ◽  
The Family ◽  
Perisoreus Canadensis ◽  
Insufficient Time ◽  
Anticosti Island ◽  
Free Environment ◽  
Late Stages

A neglected question in the study of communal breeding concerns why alloparental behaviour begins at variously late stages in the breeding cycle. In group-living corvids, the delay tends to be longer in species that are small and (or) typically have only a small nonbreeder complement. This pattern has been attributed to the relatively poor defensive capabilities of such species and their consequently greater need to minimize predator-attracting traffic to the nest or fledglings. We tested this predator avoidance hypothesis with the Canada Jay (Perisoreus canadensis (Linnaeus, 1766)), a species in which the feeding of young by any nonbreeders in the family group is delayed until the fledgling period. We reasoned that, on Anticosti Island, Quebec (Canada), in the absence of squirrels and other nest predators, nonbreeders might be permitted to feed nestlings as well as fledglings, and that breeders might feed nestlings more frequently (with smaller food loads) than on the mainland. We found no evidence for either prediction and thus no support for the predator avoidance hypothesis but suggest that Anticosti Canada Jays may have had insufficient time to evolve behaviour more appropriate for their predator-free environment. Secondarily, we confirmed that in all observed instances, the nonbreeders were offspring of the breeding pair from previous years and that they therefore failed to provision nestlings in spite of an apparent genetic interest to do so.

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