Special Issue "Small Ruminant Genetics and Breeding"

A special issue of Animals (ISSN 2076-2615). This special issue belongs to the section "Small Ruminants".

Deadline for manuscript submissions: 31 March 2022.

Special Issue Editor

Dr. Dimitrios Loukovitis
E-Mail Website
Guest Editor
Research Institute of Animal Science, ELGO ‘DEMETER’, General Directorate of Agricultural Research, Paralimni Giannitsa, 58100 Pella, Greece
Interests: genomics; SSRs; population genetics; marker assisted selection; SNPs; QTLs; molecular markers; genomic selection; aquaculture genetics; livestock genetics

Special Issue Information

Small ruminants, such as sheep (Ovis aries) and goats (Capra hircus), were among the first animals to be domesticated, with historical evidence linking them to Western Asia approximately 9000–12,000 years ago. Domesticated sheep and goats provided early humans with a supply of fiber, pelt, meat, and milk. Owing to their small stature and versatility, small ruminants have become steadily important in the global rural economy, especially in the arid and semi-arid regions. Furthermore, the demand for meat and milk in developing countries is constantly increasing, and a sustainable increase in small ruminant production would therefore be desirable in order to meet the demands of the human population on livestock populations and their products.

Genetic improvement can substantially promote the efficiency of animal production, by increasing the performance of small ruminant flocks or populations over time with the use of genetically superior animals. A prerequisite is to select the most desirable breed or breed combination, and to define the breeding objectives.

Over the last two decades, advances in DNA technology have dramatically increased the efficiency and the affordability of gaining genome information, leading to the development of fast, cost-effective, and more accurate methods for the implementation of breeding programs.

For this Special Issue, original research manuscripts covering all aspects of small ruminant genetics, such as population genetics, breed investigation and characterization, quantitative genetics, QTL and marker assisted selection, genomic selection, gene polymorphisms, and genome-wide association studies, are welcome.

Dr. Dimitrios Loukovitis
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Animals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • small ruminant
  • genetic improvement
  • population genetics
  • QTL
  • genomic selection
  • molecular markers

Published Papers (5 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Article
MicroRNA-200b Regulates the Proliferation and Differentiation of Ovine Preadipocytes by Targeting p27 and KLF9
Animals 2021, 11(8), 2417; https://doi.org/10.3390/ani11082417 - 17 Aug 2021
Viewed by 355
Abstract
MicroRNAs (miRNAs) are crucial regulatory molecules in lipid deposition and metabolism. However, the effect of miR-200b on the regulation of proliferation and adipogenesis of ovine preadipocytes is unknown in the sheep (Ovis aries). In this study, the expression profiles of miR-200b [...] Read more.
MicroRNAs (miRNAs) are crucial regulatory molecules in lipid deposition and metabolism. However, the effect of miR-200b on the regulation of proliferation and adipogenesis of ovine preadipocytes is unknown in the sheep (Ovis aries). In this study, the expression profiles of miR-200b were investigated in the seven tissues of Tibetan ewes and differentiated preadipocytes. The effect of miR-200b, as well as its target genes p27 and KLF9, on the proliferation of ovine preadipocytes and adipogenesis was also investigated, using cell viability analysis, EdU staining, Oil Red O staining and reverse transcription-quantitative PCR (RT-qRCR). The miR-200b was expressed in all the tissues investigated, and it was highly expressed in lung, liver, subcutaneous adipose and spleen tissues. The expression of miR-200b continuously decreased when the differentiation of ovine preadipocytes initiated. The miR-200b mimic dramatically accelerated the proliferation but inhibited differentiation of ovine preadipocytes. The miR-200b inhibitor resulted in an opposite effect on the proliferation and differentiation of ovine preadipocytes. The dual luciferase reporter assay results showed that miR-200b mimic significantly decreased the luciferase activity of p27 and KLF9 in HEK293 cells transfected with wild-type dual luciferase reporter vectors. This suggests that p27 and KLF9 are the target genes of miR-200b. In over-expressed-p27 preadipocytes, the number of EdU-labeled preadipocytes and the expression levels of proliferation marker genes CDK2, CDK4, CCND1 and PCNA significantly decreased. In addition, the transfection of over-expressed-KLF9 vector into adipocytes remarkably increased the accumulation of lipid droplets and the expression levels of differentiation marker genes aP2, PPARγ, LPL and GLUT4. These results suggest that miR-200b accelerated the proliferation but inhibited the adipogenic differentiation of ovine preadipocytes by targeting p27 and KLF9, respectively. Full article
(This article belongs to the Special Issue Small Ruminant Genetics and Breeding)
Show Figures

Figure 1

Article
Polymorphisms of Codons 110, 146, 211 and 222 at the Goat PRNP Locus and Their Association with Scrapie in Greece
Animals 2021, 11(8), 2340; https://doi.org/10.3390/ani11082340 - 08 Aug 2021
Viewed by 523
Abstract
Scrapie is considered an endemic disease in both sheep and goats in Greece. However, contrary to sheep, in goats more than one prion protein (PrP) polymorphism has been recognized as a candidate for resistance breeding against the disease. For an impression, candidates which [...] Read more.
Scrapie is considered an endemic disease in both sheep and goats in Greece. However, contrary to sheep, in goats more than one prion protein (PrP) polymorphism has been recognized as a candidate for resistance breeding against the disease. For an impression, candidates which are circulating, (i) brain samples (n = 525) from scrapie-affected (n = 282) and non-affected (n = 243) animals within the national surveillance program, and (ii) individual blood samples (n = 1708) from affected (n = 241) and non-affected (n = 1467) herds, in a large part of mainland Greece and its islands, were collected and assayed. A dedicated Taqman method was used to test for amino acid polymorphisms 110T/P, 146N/S/D, 211R/Q, and 222Q/K. Highly prevalent genotypes were 110TT, 146NN, 211RR, and 222QQ. The frequencies of polymorphisms in blood and negative brain samples for codons 110P, 211Q, and 222K were 4.0%, 3.0%, and 1.9%, respectively, while 146D (0.7%) was present only on Karpathos island. Codon 110P was exclusively found in scrapie-negative brains, and homozygous 110P/P in two scrapie-negative goats. It is concluded that breeding programs in Karpathos could focus on codon 146D, while in other regions carriers of the 110P and 222K allele should be sought. Case-control and challenge studies are now necessary to elucidate the most efficient breeding strategies. Full article
(This article belongs to the Special Issue Small Ruminant Genetics and Breeding)
Show Figures

Figure 1

Article
Placental Characteristics Classification of Various Native Turkish Sheep Breeds
Animals 2021, 11(4), 930; https://doi.org/10.3390/ani11040930 - 25 Mar 2021
Viewed by 497
Abstract
The aim of this study was to classify placental characteristics of Akkaraman, Morkaraman, Karayaka, Awassi, Malya, and Bafra sheep breeds using the hierarchical clustering method. In total, 240 individual data records were used as experimental material. Placental characteristics such as total cotyledon surface [...] Read more.
The aim of this study was to classify placental characteristics of Akkaraman, Morkaraman, Karayaka, Awassi, Malya, and Bafra sheep breeds using the hierarchical clustering method. In total, 240 individual data records were used as experimental material. Placental characteristics such as total cotyledon surface area, small and large cotyledon length, small cotyledon depth, etc. were used as explanatory variables to classify the breeds’ characteristics. Hierarchical clustering was used with the nearest neighbour method with Euclidean distance in order to classify the sheep breeds’ variations. As a result, six breeds were separated into three clusters: the first cluster consisted of Bafra, Karayaka, and Awassi breeds; the second consisted of Akkaraman and Malya breeds; and the third cluster included only the Morkaraman breed. Bafra and Karayaka were pointed as the nearest breeds, with a similarity of 98.7% in terms of placental characteristics. The similarity rate of the Akkaraman and Malya breeds was at a level of 97.5%, whereas it was 96.8% for Bafra, Karayaka, and Awassi breeds. The similarity of Akkaraman, Karayaka, Awassi, Malya, and Bafra sheep breeds was estimated as 95.7%. The overall similarity was found to be at a level of 93.2% among sheep breeds. The outcomes of the study might be useful as a selection tool for reproductivity and can be used to select the breed to be reared. Full article
(This article belongs to the Special Issue Small Ruminant Genetics and Breeding)
Show Figures

Figure 1

Article
The LEPR Gene Is Associated with Reproductive Seasonality Traits in Rasa Aragonesa Sheep
Animals 2020, 10(12), 2448; https://doi.org/10.3390/ani10122448 - 21 Dec 2020
Cited by 1 | Viewed by 708
Abstract
The aim of this study was to characterize and identify causative polymorphisms in the leptin receptor (LEPR) gene responsible for the seasonal variation of reproductive traits in sheep. Three reproductive seasonality traits were studied: the total days of anoestrous (TDA), the [...] Read more.
The aim of this study was to characterize and identify causative polymorphisms in the leptin receptor (LEPR) gene responsible for the seasonal variation of reproductive traits in sheep. Three reproductive seasonality traits were studied: the total days of anoestrous (TDA), the progesterone cycling months (P4CM) and the oestrous cycling months (OCM). In total, 18 SNPs were detected in 33 ewes with extreme values for TDA and OCM. Six SNPs were non-synonymous substitutions and two of them were predicted in silico as deleterious: rs596133197 and rs403578195. These polymorphisms were then validated in 239 ewes. The SNP rs403578195, located in exon 8 and leading to a change of alanine to glycine (Ala284Gly) in the extracellular domain of the protein, was associated with the OCM trait, being the G allele associated with a decrease of 12 percent of the OCM trait. Haplotype analyses also suggested the involvement of other non-synonymous SNP located in exon 20 (rs405459906). This SNP also produces an amino acid change (Lys1069Glu) in the intracellular domain of the protein and segregates independently of rs403578195. These results confirm for the first time the role of the LEPR gene in sheep reproductive seasonality. Full article
(This article belongs to the Special Issue Small Ruminant Genetics and Breeding)
Show Figures

Figure 1

Article
Genetic Signatures of Selection for Cashmere Traits in Chinese Goats
Animals 2020, 10(10), 1905; https://doi.org/10.3390/ani10101905 - 18 Oct 2020
Cited by 1 | Viewed by 725
Abstract
Inner Mongolia and Liaoning cashmere goats in China are well-known for their cashmere quality and yield. Thus, they are great models for identifying genomic regions associated with cashmere traits. Herein, 53 Inner Mongolia cashmere goats, Liaoning cashmere goats and Huanghuai goats were genotyped, [...] Read more.
Inner Mongolia and Liaoning cashmere goats in China are well-known for their cashmere quality and yield. Thus, they are great models for identifying genomic regions associated with cashmere traits. Herein, 53 Inner Mongolia cashmere goats, Liaoning cashmere goats and Huanghuai goats were genotyped, and 53,347 single-nucleotide polymorphisms (SNPs) were produced using the Illumina Caprine 50K SNP chip. Additionally, we identified some positively selected SNPs by analyzing Fst and XP-EHH. The top 5% of SNPs had selection signatures. After gene annotation, 222 and 173 candidate genes were identified in Inner Mongolia and Liaoning cashmere goats, respectively. Several genes were related to hair follicle development, such as TRPS1, WDR74, LRRC14, SPTLC3, IGF1R, PADI2, FOXP1, WNT10A and CSN3. Gene enrichment analysis of these cashmere trait-associated genes related 67 enriched signaling pathways that mainly participate in hair follicle development and stem cell pluripotency regulation. Furthermore, we identified 20 overlapping genes that were selected in both cashmere goat breeds. Among these overlapping genes, WNT10A and CSN3, which are associated with hair follicle development, are potentially involved in cashmere production. These findings may improve molecular breeding of cashmere goats in the future. Full article
(This article belongs to the Special Issue Small Ruminant Genetics and Breeding)
Show Figures

Figure 1

Back to TopTop