SLE254 Genetics and Genomics Practical: Chicken Sex Determination

This practical assignment details the process of determining the sex of domestic chickens (Gallus gallus) using PCR-based techniques. The study focuses on the CHD1 gene, which is located on the sex chromosome. DNA was extracted from various tissue samples, including blood, feathers, and muscle, using different methods. The concentration and quality of the extracted DNA were assessed, with blood showing the highest concentration. PCR amplification of the CHD1 gene was performed, and the products were visualized using gel electrophoresis to differentiate between male (ZZ) and female (ZW) chickens. The results indicated successful sex identification based on the presence or absence of specific bands, with discussions focusing on the efficiency of different tissue types for DNA extraction and the implications for breeding and poultry management. The assignment includes methods, results, and discussion sections, along with references and acknowledgments.

SLE254 GENETICS AND GENOMICS
DETERMINING THE SEX OF THE DOMESTIC CHICKEN (GALLUS GALLUS)
NAME:
INTRODUCTION
AIMS & OBJECTIVES
METHODS
 The determination of sex in the pure breed chickens at an early age is a vital task
in order to reduce feeding cost of the unwanted sex, diminishing the labour cost,
accomplishing sex specific programmes of feeding along with commercialization
of the pure breed lines of birds based on the sex. (Klein et al. 2003; Damme and
Ristic 2003).
 The Polymerase Chain Reaction or the PCR based sex determination
techniques are regularly used to ascertain the sex of the parent lines in the
breeding industries, nevertheless purified DNA is essential.
 The chickens follow a Z-W type sex chromosome system with females as ZW
and homogametic males as ZZ.
 Chromo helicase DNA binding gene 1 or CHD1 is a gene on the sex
chromosome which is the specific gene targets for sex determination in the
chicken.
 As the CHD1 is larger on Z chromosome than on the W chromosome. The
male is highlighted as 1 band(ZZ) and female as 2 bands(ZW) in the gel
electrophoresis (Dhanasekaran et al. 2016).
RESULTS
DISCUSSIONS
UNIVERSITY LOGO
REFERENCES
ACKNOWLEDGEMENTS:
DNA
extracted
Number of
samples
Mean DNA
concentration
(ng/μl)
Average
260/280
ratio
Blood 9 78.05778 2.104333
Feather 11 30.35364 1.531545
Muscle 13 31.47462 1.967615
Table 1: The table summarizes the mean
concentration of DNA along with the mean A260/280
ratio averaged based on the total number of tissue
samples from which DNA was extracted.
Figure 3: The above figure
highlights the DNA extracted
from feather of the chicken.
Figure 4: The figure evidences the gender
identification of chicken with the aid of
PCR amplification of the CHW1 gene from
chicken feather. The gel was ran with
female and male controls which also
acted as the positive controls of the PCR.
Figure 1: The figure illustrates mean concentration of
DNA extracted from different chicken tissue samples.
Figure 2: The figure elucidates average A260/280 ratio
of the DNA extracted from different chicken tissues.
Marker
Marker
Male Control
Female Control
Sample 1 negative
Sample 2
Sample 3
Sample 4
Sample 5
Sample 6
Sample 7
Sample 8
Sample 9
Sample 10
Sample 11
Marker
Sample 1
Sample 2
Sample 3
Sample 4
Sample 5
Sample 6
Sample 7
Sample 8
Sample 9
Sample 10
Sample 11
Sample 12
Sample 13
Sample 14
Sample 15
 The study aims to extract DNA via non invasive non destructive method
(feather); invasive non destructive method (blood); invasive and destructive
method (muscles) from the chicken.
 The main objective of the study is to determine the sex of the chicken from the
tissue samples collected.
 DNA extraction and visualization: The method of DNA extraction varied for
different tissue types. The methodological details are given in Hogan et al.
2018.
 PCR amplification of the extracted DNA with CHD1 specific primers.
 Visualisation of the PCR products to determine the sex of the chicken on 1.5
percent agarose gel electrophoresis. Damme, K. and Ristic, M. 2003. Fattening performance, meat yield and economic aspects of meat
and layer type hybrids. World's Poultry Science Journal 59: 50-52.
Dhanasekaran, S., Raj, G.D., Vignesh, A.R., Selvan, S.T., Prakash, B., Perumal, P., Arivudainambi, S.
and Babu, T.G., 2016. Gender identification in Chicken (Gallus gallus) by PCR using whole blood
and dried blood spot on filter paper as template: without prior DNA isolation. bioRxiv, p.046888.
Hogan F, LokeS, and Sherman C (2018), SLE254 Genetics practical manual 2018, Deakin
University.
Klein, S; Baulain, U; Rokitta, M; Marx, G; Thielebein, J; Ellendorff, F., 2003: Sexing the freshly laid
egg development of embryos after manipulation; analytical approach and localization of the
blastoderm in the intact egg. World's poultry science journal 59 (1): 39-45
 Figure 1 highlights that the concentration of extracted DNA is
highest from the blood drawn from the chicken. The highest DNA
concentration is noted, followed by muscle and least DNA
concentration is noted in feathers.
 Figure 2 illustrates the samples 2, 5, 6 and 7 have been identified
as female and samples 3, 4, 8 have been identified as male.
 Lack of DNA or less concentration of DNA in samples might be due
to difficulty of tissue processing for DNA extraction from feathers
and muscles.
 A common problem in collecting blood samples for DNA
isolation is preservation of DNA from degradation, therefore
DNA extraction from feathers might be preferred which is also
non invasive and non destructive (Dhanasekaran et al. 2016).