Application of microsatellite genotyping by sequencing (SSR-GBS) to measure genetic diversity of the East African Oreochromis niloticus

Abstract Background The need for enhancing the productivity of fisheries in Africa triggered the introduction of non-native fish, causing dramatic changes to local species. In East Africa, the extensive translocation of Nile tilapia (Oreochromis niloticus) is one of the major factors in this respect. Using 40 microsatellite loci with SSR-GBS techniques, we amplified a total of 664 individuals to investigate the genetic structure of O. niloticus from East Africa in comparison to Ethiopian and Burkina Faso populations. Results All three African regions were characterized by independent gene-pools, however, the Ethiopian population from lake Tana showed to be more divergent than expected suggesting that it might be a different species. In East Africa, the genetic structure was congruent with both geographical location and anthropogenic activities. O. niloticus from Lake Turkana (Kenya) was isolated, while in Uganda, despite populations being rather similar to each other, two main natural catchments were able to be defined. We show that these two groups contributed to the gene-pool of different non-native populations. Moreover, admixture and possible hybridization with other tilapiine species may have contributed to the genetic divergence found in some populations such as Lake Victoria. We detected other factors that might be affecting Nile tilapia genetic variation. For example, most of the populations have gone through a reduction of genetic diversity, which can be a consequence of bottleneck caused by overfishing, genetic erosion due to fragmentation or founder effect resulting from stoking activities. Conclusions The anthropogenic activities particularly in the East African O. niloticus translocations, promoted admixture and contact with the native congenerics which may contribute to outbreeding depression and hence compromising the sustainability of the species in the region.

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Molecular genetic diversity and differentiation of Nile tilapia (Oreochromis niloticus, L. 1758) in East African natural and stocked populations

10.21203/rs.2.11849/v3 ◽

2019 ◽

Author(s):

Papius Dias Tibihika ◽

Manuel Curto ◽

Esayas Alemayehu ◽

Herwig Waidbacher ◽

Charles Masembe ◽

...

Keyword(s):

Genetic Diversity ◽

Genetic Structure ◽

East Africa ◽

Oreochromis Niloticus ◽

Nile Tilapia ◽

Anthropogenic Activities ◽

Genetic Erosion ◽

Gene Pools ◽

East African ◽

Nile Tilapia Oreochromis Niloticus

Abstract Background The need for enhancing the productivity of fisheries in Africa triggered the introduction of non-native fish, causing dramatic changes to local species. In East Africa, the extensive translocation of Nile tilapia (Oreochromis niloticus) is one of the major factors in this respect. Using 40 microsatellite loci with SSR-GBS techniques, we amplified a total of 664 individuals to investigate the genetic structure of O. niloticus from East Africa in comparison to Ethiopian and Burkina Faso populations. Results All three African regions were characterized by independent gene-pools, however, the Ethiopian population from lake Tana showed to be more divergent than expected suggesting that it might be a different species. In East Africa, the genetic structure was congruent with both geographical location and anthropogenic activities. O. niloticus from Lake Turkana (Kenya) was isolated, while in Uganda, despite populations being rather similar to each other, two main natural catchments were able to be defined. We show that these two groups contributed to the gene-pool of different non-native populations. Moreover, admixture and possible hybridization with other tilapiine species may have contributed to the genetic divergence found in some populations such as Lake Victoria. We detected other factors that might be affecting Nile tilapia genetic variation. For example, most of the populations have gone through a reduction of genetic diversity, which can be a consequence of bottleneck caused by overfishing, genetic erosion due to fragmentation or founder effect resulting from stoking activities. Conclusions The anthropogenic activities particularly in the East African O. niloticus translocations, promoted admixture and contact with the native congenerics which may contribute to outbreeding depression and hence compromising the sustainability of the species in the region.

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Molecular genetic diversity and differentiation of Nile tilapia (Oreochromis niloticus, L. 1758) in East African natural and stocked populations

BMC Evolutionary Biology ◽

10.1186/s12862-020-1583-0 ◽

2020 ◽

Vol 20 (1) ◽

Cited By ~ 2

Author(s):

Papius Dias Tibihika ◽

Manuel Curto ◽

Esayas Alemayehu ◽

Herwig Waidbacher ◽

Charles Masembe ◽

...

Keyword(s):

Genetic Diversity ◽

Oreochromis Niloticus ◽

Nile Tilapia ◽

Molecular Genetic ◽

East African ◽

Molecular Genetic Diversity ◽

Nile Tilapia Oreochromis Niloticus

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Molecular genetic diversity and differentiation of Nile tilapia (Oreochromis niloticus, L. 1758) in East African natural and stocked populations

10.21203/rs.2.11849/v1 ◽

2019 ◽

Author(s):

Papius Dias Tibihika ◽

Manuel Curto ◽

Esayas Alemayehu ◽

Herwig Waidbacher ◽

Charles Masembe ◽

...

Keyword(s):

Genetic Diversity ◽

Genetic Structure ◽

East Africa ◽

Oreochromis Niloticus ◽

Nile Tilapia ◽

Anthropogenic Activities ◽

Genetic Erosion ◽

Gene Pools ◽

East African ◽

Nile Tilapia Oreochromis Niloticus

Abstract Background The need for enhancing the productivity of fisheries in Africa triggered the introduction of non-native fish, causing dramatic changes to local species. In East Africa, the extensive translocation of Nile tilapia (Oreochromis niloticus) is one of the major factors in this respect. Using 40 microsatellite loci with SSR-GBS techniques, we amplified a total of 664 individuals to investigate the genetic structure of O. niloticus from East Africa in comparison to Ethiopian and Burkina Faso populations. Results All three African regions were characterized by independent gene-pools, however, the Ethiopian population from lake Tana showed to be more divergent than expected suggesting that it might be a different species. In East Africa, the genetic structure was congruent with both geographical location and anthropogenic activities. O. niloticus from Lake Turkana (Kenya) was isolated, while in Uganda, despite populations being rather similar to each other, two main natural catchments were able to be defined. We show that these two groups contributed to the gene-pool of different non-native populations. Moreover, admixture and possible hybridization with other tilapiine species may have contributed to the genetic divergence found in some populations such as Lake Victoria. We detected other factors that might be affecting Nile tilapia genetic variation. For example, most of the populations have gone through a reduction of genetic diversity, which can be a consequence of bottleneck caused by overfishing, genetic erosion due to fragmentation or founder effect resulting from stoking activities. Conclusions The anthropogenic activities particularly in the East African O. niloticus translocations, promoted admixture and contact with the native congenerics which may contribute to outbreeding depression and hence compromising the sustainability of the species in the region.

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Molecular genetic diversity and differentiation of Nile tilapia (Oreochromis niloticus, L. 1758) in East African natural and stocked populations

10.21203/rs.2.11849/v4 ◽

2020 ◽

Author(s):

Papius Dias Tibihika ◽

Manuel Curto ◽

Esayas Alemayehu ◽

Herwig Waidbacher ◽

Charles Masembe ◽

...

Keyword(s):

Genetic Diversity ◽

Genetic Structure ◽

East Africa ◽

Oreochromis Niloticus ◽

Nile Tilapia ◽

Anthropogenic Activities ◽

Genetic Erosion ◽

Gene Pools ◽

East African ◽

Nile Tilapia Oreochromis Niloticus

Abstract Background The need for enhancing the productivity of fisheries in Africa triggered the introduction of non-native fish, causing dramatic changes to local species. In East Africa, the extensive translocation of Nile tilapia (Oreochromis niloticus) is one of the major factors in this respect. Using 40 microsatellite loci with SSR-GBS techniques, we amplified a total of 664 individuals to investigate the genetic structure of O. niloticus from East Africa in comparison to Ethiopian and Burkina Faso populations. Results All three African regions were characterized by independent gene-pools, however, the Ethiopian population from lake Tana showed to be more divergent than expected suggesting that it might be a different species. In East Africa, the genetic structure was congruent with both geographical location and anthropogenic activities. O. niloticus from Lake Turkana (Kenya) was isolated, while in Uganda, despite populations being rather similar to each other, two main natural catchments were able to be defined. We show that these two groups contributed to the gene-pool of different non-native populations. Moreover, admixture and possible hybridization with other tilapiine species may have contributed to the genetic divergence found in some populations such as Lake Victoria. We detected other factors that might be affecting Nile tilapia genetic variation. For example, most of the populations have gone through a reduction of genetic diversity, which can be a consequence of bottleneck caused by overfishing, genetic erosion due to fragmentation or founder effect resulting from stoking activities. Conclusions The anthropogenic activities particularly in the East African O. niloticus translocations, promoted admixture and contact with the native congenerics which may contribute to outbreeding depression and hence compromising the sustainability of the species in the region.

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Genetic Diversity of Purple Passion Fruit, Passiflora edulis f. edulis, Based on Single-Nucleotide Polymorphism Markers Discovered through Genotyping by Sequencing

Diversity ◽

10.3390/d13040144 ◽

2021 ◽

Vol 13 (4) ◽

pp. 144

Author(s):

Nohra Castillo Rodríguez ◽

Xingbo Wu ◽

María Isabel Chacón ◽

Luz Marina Melgarejo ◽

Matthew Wohlgemuth Blair

Keyword(s):

Genetic Diversity ◽

Single Nucleotide Polymorphism ◽

Genotyping By Sequencing ◽

Passion Fruit ◽

Nucleotide Polymorphism ◽

Single Nucleotide ◽

Passiflora Edulis ◽

Tropical Fruit ◽

Commercial Cultivars ◽

Purple Passion Fruit

Orphan crops, which include many of the tropical fruit species used in the juice industry, lack genomic resources and breeding efforts. Typical of this dilemma is the lack of commercial cultivars of purple passion fruit, Passiflora edulis f. edulis, and of information on the genetic resources of its substantial semiwild gene pool. In this study, we develop single-nucleotide polymorphism (SNP) markers for the species and show that the genetic diversity of this fruit crop has been reduced because of selection for cultivated genotypes compared to the semiwild landraces in its center of diversity. A specific objective of the present study was to determine the genetic diversity of cultivars, genebank accession, and landraces through genotyping by sequencing (GBS) and to conduct molecular evaluation of a broad collection for the species P. edulis from a source country, Colombia. We included control genotypes of yellow passion fruit, P. edulis f. flavicarpa. The goal was to evaluate differences between fruit types and compare landraces and genebank accessions from in situ accessions collected from farmers. In total, 3820 SNPs were identified as informative for this diversity study. However, the majority distinguished yellow and purple passion fruit, with 966 SNPs useful in purple passion fruits alone. In the population structure analysis, purple passion fruits were very distinct from the yellow ones. The results for purple passion fruits alone showed reduced diversity for the commercial cultivars while highlighting the higher diversity found among landraces from wild or semi-wild conditions. These landraces had higher heterozygosity, polymorphism, and overall genetic diversity. The implications for genetics and breeding as well as evolution and ecology of purple passion fruits based on the extant landrace diversity are discussed with consideration of manual or pollinator-assisted hybridization of this species.

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