Identification Of Variations In The Coding Region Of Myostatin Gene In Thalli And Pakkarakul Sheep Breeds Of The Punjab
Material type: Book ; Literary form:
Publisher: 2015 Dissertation note: In a developing country like Pakistan, livestock sector has a significant importance.
Meat is an important food component in human diet and its source varies from different
organisms like cattle, buffalo, camel, deer, sheep, goat, rabbit and chicken etc. Small
ruminants especially sheep, has a unique role in meat production, due to its feeding and
adaptive behavior. The myostatin (MSTN) gene is known as a candidate gene for
development and growth of livestock because it plays its major role in muscle growth.
Selection is an important tool to improve the meat production and thus enhance the economic
conditions of livestock farmers. For this purpose genetically characterization of meat type
animals, especially the indigenous sheep breeds is not common. The variations in the
myostatin gene have been extensively studied and reviewed in small and large ruminants in
the world but it has been scanty studied in sheep breeds of Pakistan. Thalli and Pak-Karakul
are well known sheep breeds present in Punjab, Pakistan. This study aims to characterize the
genetic variation in the myostatin gene in Thalli and Pak-Karakul sheep breeds.
In this research study, twenty adult animals of two different sheep breeds (Thalli and
Pak-Karakul) were selected from Small Ruminants Research and development Centre, Rakh
Khairewala, District Layyah, Pakistan. Five mL blood sample was collected from each
animal in a 15mL falcon tube containing anticoagulant. Primers were designed by using
Primerfox online software. Primers were optimized using specific protocol and PCR was
performed. DNA was extracted using modified inorganic method of Sambrook et al. (1989).
PCR was carried out using all primers and later sent for sequencing to 1stBase Laboratories,
Singapore. Molecular analysis was done using CodonCode Aligner and MEGA6 softwares.
Ten samples of each breed were sequenced to detect polymorphism in both Thalli and
Pak-Karakul sheep populations. Sequencing revealed G↓T transition at 3995 position in
genome (accession number, DQ530260.1) in Thalli and similar transition in Pak-Karakul at
the same position. In Thalli sheep 50 % of experimental animals were heterozygous, higher
level of heterozygosity makes it a potential candidate for higher growth rates. On the other
hand the Pak-Karakul sheep is medium weight breed and frequency of mutant allele was 0.2
or 20%. The observed heterozygous individuals were also with higher live body weights. The
gene frequency shows that this breed has medium potential for its body growth. The
information‟s so generated and further association studies in both breeds will be helpful in
devising breeding plans for increasing mutton production at national level.
Availability: Items available for loan: UVAS Library [ Call number: 2288-T] (1).
Morphological Structure Of Thalli Sheep Through Principal Component Analysis Of Body Measurements Muhammad
Material type: Book ; Literary form:
Publisher: 2016 Dissertation note: Mutton is also very extensively used food and sources of mutton are only sheep and goat.
Sheep have a great genetic potential to fulfill the increasing demand of mutton in our country.
Body conformation and features are very important traits in milch, meat and wool animals. In
developing countries, record keeping is at initial level and the records about pedigree and progeny
of individuals are insufficient and do not provide the estimation about genetic parameters.
Therefore, phenotypic information are necessary for the explanation of relationship among linear
type traits and selection is based on these traits. Principal component analysis technique has been
used to identify the body size, body shape, head size and over all body conformation in Zulu Sheep.
Animal conformation and genetic parameters can be measured by using the technique of
Data on morphometric traits of Thalli sheep were collected from “Small Ruminant
Research and Development Centre, Rakh Khairewala, District Layyah, Punjab, Pakistan” and
Livestock Experiment Station, Rakh Ghulaman, District Bhakkar, Punjab, Pakistan. Different
phenotypic parameters and twenty one (21) morphometric traits were measured on animals of
Thalli sheep. The traits measured were birth weight, body weight, heart girth, body length, withers
height, head length, head width, ear length, ear width, neck length, neck width, barrel depth, sacral
pelvic width, rump length, rump width, tail length, testes length, testes width, scrotal diameter, teat
length and teat diameter. Different phenotypic characters was recorded as body color, body shape,
eye color, head color, fore head color, face color, face structure, chin color, ear color, ear nature,
appendages color, nostril structure, muzzle structure, neck structure, tail color and tail switch.
Weighing balance (digital) was used for determination of body weight and a flexible
measuring tape (tailor tape) was used to record the different body measurements. To avoid
variations among individuals, measurements were taken by the same person. Animals of different
age groups were reared at these research stations. Animals were divided into different groups (A,
B, C, D, E, F, G, H and I) according to their age as 0-3, 4-6, 7-9, 10-12, 13-15, 16-18, 19-21, 22-
24 and above 24 months. Each group was further divided into two sub-groups of males and females
animals. Normality of data were checked against all animals (overall group and separate groups)
and all animals were fallen in ±3SD but two outliers had been removed. Data on morphometric
traits were analyzed statistically for mean, range, coefficient of variation and standard error.
Pearson’s coefficient of correlation among different biometric traits was estimated and data were
generated for principal component analysis (PCA) from the correlation matrix. Regression
equations were developed for the estimation of body weight.
Descriptive statistics (mean, range, standard deviation and coefficient of variation) of body
measurements of overall female were showed coefficient of variations of overall female animals
of Thalli sheep for mostly variables were ranged from 10-20% and coefficient of variations of birth
weight and body weight were 22.38% and 25.75% respectively. Coefficient of variations of male
animals of Thalli sheep for linear body measurements were ranged 08-25% and tail length had
high coefficient of variations as 26.89%. Male animals of all age groups are heavier than females.
Correlation coefficients of morphometric traits of overall females and males of Thalli sheep
were highly positive and significant (P≤0.01) among withers height, body length, heart girth, head
length, head width, ear length, neck length, neck width, rump length, rump width, barrel depth,
sacral pelvic width and body weight. Withers height, heart girth and body length were observed to
be significantly correlated with each other as well as with live body weight of all age groups.
For overall female animals, two principal components were extracted with eigenvalues
9.005 and 1.558 and 56.279% and 9.740% variances for PC1 and PC2 respectively and their
cumulative variance was 66.020%. For overall male animals, three principal components were
extracted with eigenvalues greater than 1 and PC1 showed high variance 57.516% and PC2 and
PC3 had variances as 12.184% and 7.022% respectively and their cumulative was components
76.721%. In all age groups which has been studied, withers height, body length and heart girth
have high values in commonalities as well as in component matrix. PC1, PC2 and PC3 showed
maximum variations in almost all age group studied.
Regression equations developed to estimate of live weight of all age groups were indicated
that almost all equations had variables withers height, body length and heart girth.
From findings of present study, it was concluded that body measurements (Withers height,
body length and heart girth) had high correlations with each other and with body weight in almost
all age groups. Principal component analysis of morphometric traits was showed that most of
variation explained by PC1 and in some groups, PC2 and PC3 had also more effects.
Commonalities were higher which showed that all the variables were important but PC1 had high
values for withers height, body length and heart girth and maximum variance. This indicated that
morphometric traits are very important for selection of genetically elite animals. Morphometric
traits can be used to estimate the body weight in the field conditions, where weighing balance is
not usually available. However, further research is needed to investigate the relationship among
different morphometric traits in other breeds of goats, sheep and other livestock breeds like cattle,
buffalo, camel and horse of the country.
Availability: Items available for loan: UVAS Library [ Call number: 2471-T] (1).