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Mismatch Cleavage by CEL-I Endonuclease:
A Tool for Rapid Detection of Homozygous
and Heterozygous Mutants
-- Sulabha Sharma, Kamal Tyagi, M Lakshmi Narasu,
Y Sreelakshmi and Rameshwar Sharma
In recent years, mutants have served as useful starting material to unravel the mechanisms governing many
biological processes, including both plants and animals. Mainly, there are three ways of inducing mutations; by using
physical agents (radiations UV, X-rays, g-rays), chemical agents (Ethyl Methane Sulphonate (EMS), Nitrous Oxide (NO),
acridine, etc.) and biological agents (transposon and T-DNA). The mutation induced by these agents lead to isolation of
most commonly recessive or uncommonly dominant mutants. The isolation and screening of a mutant are tedious
besides being a cumbersome job. Even after isolation, ascertaining the homozygous nature of the plant is equally
difficult, especially for a dominant mutant. The commonly known methods for screening of homo/heterozygosity of
the mutant are either highly expensive as sequencing of the gene or involve very tedious/time-consuming genetic
segregation analysis. Here, we present a rapid tool for identifying the homo/heterozygous nature of the plants by simple
digestion of PCR-amplified genomic DNA with CEL-I endonuclease and resolving the cleaved product on conventional
agarose gels. This method is quite robust and provides a great help to researchers in developing countries
where instrumentation access is limited.
© 2011 IUP. All Rights Reserved.
Association of ADAM33 Gene Polymorphisms
with Reduction of Lung Function as Measured
by Peak Expiratory Flow Rate Among Healthy
Male Smokers and Nonsmokers
-- Priya Tripathi, Shally Awasthi and Subramaniam Ganesh
ADAM33 gene, which comes in ADAM (a disintegrin and metalloprotease) gene family, is an asthma susceptibility
gene and has been associated with impaired lung function. Therefore, we aimed to investigate association of five
ADAM33 polymorphisms (F+1 (rs511898) G/A, S2 (rs528557) G/C, ST+4 (rs44707) A/C, ST+5 (rs597980) C/T and V4
(rs2787094) C/G) with lung function, as assessed by peak expiratory flow (PEF) meter in normal healthy male population
recruited from among students and employee volunteers in the age group of 16 to 50 year, including smokers and
nonsmokers. SNPs were genotyped with the help of restriction fragment length polymorphism-polymerase chain reaction
(RFLP-PCR) method. Of 201 healthy males recruited, 50 (24.9%) were smokers and 151 (75.1%) were nonsmokers.
Smokers had statistically significant lower values of PEFR as compared to nonsmokers. With lowest values in those smoking
> 10 cigarettes/day compared to those smoking 1-2 and
2-10 cigarettes/day (p < 0.001 and < 0.035, respectively). Only among smokers, mean difference of PEFR
was statistically significantly lower in heterozygous genotypes when compared to mutants of SNP V4
(p = 0.033). This may possibly be explained on the basis of gene-environmental interaction and further research is needed in this area.
© 2011 IUP. All Rights Reserved.
Some Investigations on Sampling Variance
of Genetic Correlation
-- S D Wahi and A R Rao
The present investigation is an attempt to compare the estimated, predicted, empirical and bootstrap Standard
Errors (SE) for different combinations of population heritability, genetic and phenotypic correlations for different
family sizes and structures under half-sib mating design. The data under half-sib model are simulated by taking sire
effects following normal as well as gamma distribution. It is observed that the empirical SE of genetic correlation, when
sire effects are from gamma distribution, are invariably higher as compared to the data with sire effects following
normal distribution irrespective of the sample size, heritability and genetic correlation of the traits. The empirical SE
of estimates of genetic correlation are very high for lowly heritable traits for whole range of genetic correlation.
The large sample approximation of SE given by Tallis is always underestimating the SE even for large family size of 30 to
50 and should not be used in practice. Barring small sample size, the bootstrap estimates of SE are very close to
predicted SE and can be used as an estimate of SE of genetic correlation. The bootstrap estimates of SE of genetic correlation
are found to be very close to the predicted SE for sample size 500 and above in case of lowly heritable traits for
whole range of genetic correlation. In case of moderately and highly heritable traits, the bootstrap estimates of SE are
found very close to predicted SE for all values of genetic correlation and for all the sample sizes and family structures
except for small sample size with moderately heritable traits. Hence, it can be concluded that the bootstrap estimates of
SE which are very close to predicted values can be used to estimate the SE instead of approximate formulae given
in literature. It is also found that in case of non-normal datasets with sire effects following gamma distribution
the bootstrap estimates of SE of genetic correlation are always underestimated.
© 2011 IUP. All Rights Reserved.
A Study of Callogenesis and Morphogenesis in Phyllanthus niruri L.
-- Lawa Hari Nepal, R Basavaraju and R S Sai Murali
Phyllanthus niruri is a very well-known medicinal plant used against jaundice and other ailments since times
immemorial. The morphogenic response of Phyllanthus
niruri was carried out in MS medium with BA, IBA, NAA, Ad, 2, 4-D and Kn.
The nodal explants treated with BA showed good establishment and also the formation of multiple shoots up to 20 in
2 mgL_1. Nodal explants with IBA treatment revealed good establishment and also produced multiple
shoots around 15-16 in 3 mgL_1. The nodal explants in the treatments of BA +
Kn and
IBA + Kn revealed good organogenesis in MS medium. The combination of NAA +
Kn and 2,
4-D + Kn revealed significant callogenesis. In the treatment of NAA 2
mgL_1 and 3 mgL_1, explants resulted in
callus formation and few shoots. Ad treatment showed good shoot and root as well as callus. Apical meristem was also tried
with BA, IBA, NAA and Ad. In BA and IBA (2
mgL_1 and 3 mgL_1), treatment multiple shoots were observed with little
callus, whereas the treatment of Ad (2
mgL_1 and 3 mgL_1) produced shoots, roots and also callus. Nodal explants and
apical meristem/terminal bud in MS medium with coconut milk exhibited good shoot, root growth and formation of
some amount of callus in 10 mLL_1.
© 2011 IUP. All Rights Reserved.
Heavy Metal Resistance Among Azotobacter Spp
and Their Survival in HM Contaminated Soil
Using Indian Mustard
-- Neeru Narula, Rishi K Behl and Erika Kothe
Seventeen different Azotobacter isolates/mutants were checked for their resistance to various Heavy Metals (HM)
(which are predominate in contaminated wismut
soil) on agar media plates containing 0.02, 0.1, 1-3 mM of Al, Pb, Ni, Cr and
Cd. Wismut soil contains nearly 39 HM of different concentrations. Among 17 isolates tested,
all were found to be resistant to all the metals at lower concentrations except Ni and Cd and percentage resistance was 70.6
(0.02-0.1 mM). At higher concentrations (1 mM-3 mM), isolates were positive except Ni and Cd where none of the
isolates were growing. The results revealed that HM resistance property is high among Azotobacter isolates. The survival of resistant bacteria inoculated on Indian mustard
(B. juncea) under green house conditions was also determined.
High bacterial numbers were observed in garden soil with and without inoculation, whereas contaminted soil showed
low bacterial numbers. The root and shoot weight
was more in the inoculated plants grown in wismut soil compared
to garden soil. Low microbial numbers in contaminated soil might be due to HM adapted bacteria have better
interaction with the plant.
© 2011 IUP. All Rights Reserved.
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