What are the chromosomes of Drosophila?
THE basic karyotype of Drosophila melanogaster, which can be seen in mitotically active neuroblasts of the larval brain, is comprised by four chromosomes, the X and Y sex chromosomes, two larger autosomal elements, chromosomes 2 and 3, and the small dot fourth chromosome (Figure 1) (Metz 1914; Deng et al. 2007) .
What is bar eye mutation in Drosophila?
One interesting case was the Drosophila Bar mutation (Tice 1914). While normal flies have round eyes, the X-linked mutation Bar (B) caused the eyes to be small and slit-like in males and homozygous females; female heterozygotes had kidney bean-shaped eyes (Figure 1A).
What causes scarlet eyes in Drosophila?
In the eyes of Drosophila, the pigments responsible for eye color are produced by two biochemical pathways: the ommochrome pathway producing a brown pigment, and the pteridine pathway first passing through a pale blue then yellow pigment stages producing a bright red (scarlet) pigment called drosopterin.
What causes vestigial wings in Drosophila?
Flies with vestigial wings cannot fly: they have a defect in their “vestigial gene,” on the second chromosome. These flies have a recessive mutation. Of the pair of vestigial genes carried by each fly (one from each parent), both have to be altered to produce the abnormal wing shape.
Why is XXY female in Drosophila?
In Drosophila, XXY represents a female but in human it is an abnormal male, because Y chromosomes are essential for determining the sex of the individual. Normally male individual possess X and Y chromosomes and female have XX chromosomes. Therefore individual having XXY genotype is an abnormal male.
How many chromosome pairs are in Drosophila?
It has only four pairs of chromosomes – three autosomes, and one pair of sex chromosomes.
Is Bar eye dominant or recessive?
dominant trait
Bar eyes (B, X; 57.0) are an X- linked dominant trait.
Are bar eyes dominant or recessive in fruit flies?
dominant
Bar is a dominant mutation causing premature arrest of the furrow, which results in the deep anterior nick in the adult eye.
What is the w1118 gene?
we(g)/w1118 is an enhancer of abnormal eye color phenotype of g53d. (Lloyd et al., 2002) we(g)/w1118 is an enhancer of abnormal eye color phenotype of g2. (Lloyd et al., 2002)
What is the scarlet gene?
A homologue of the Drosophila melanogaster eye-colour gene, scarlet (st), has been isolated from the genome of the tephritid fruit fly, Bactrocera tryoni. The comparison of the B. tryoni and D. melanogaster scarlet gene shows 71.2% and 79.3% sequence identity at the DNA and the derived amino acid level, respectively.
What is the difference between Apterous and vestigial?
Apterous Versus Vestigial
Additionally, apterous fruit flies are different from other flightless fruit flies. For example, vestigial-winged fruit flies possess stunted, deformed wings that don’t allow for flight. Apterous flies have no wings whatsoever.
Is vestigial wings dominant or recessive?
recessive
The dominant V allele produces long wings, whereas the recessive v allele produces vestigial wings.
What are Sexlinked chromosomes?
Sex Linked
Sex-linked, as related to genetics, refers to characteristics (or traits) that are influenced by genes carried on the sex chromosomes. In humans, the term often refers to traits or disorders influenced by genes on the X chromosome, as it contains many more genes than the smaller Y chromosome.
Which type of mutation causes Cri du Chat Syndrome?
Cri-du-chat syndrome is caused by a deletion of the end of the short (p) arm of chromosome 5. This chromosomal change is written as 5p-.
How many chromosomes are there in each stage of mitosis in Drosophila?
The fruit fly, Drosophila melanogaster, has a total of eight chromosomes (four pairs) in each of its somatic cells. Somatic cells are all cells of the body except those that will divide to form the gametes (ova or sperm). Review the events that occur in the various stages of mitosis. 7.
Where is polytene chromosome found?
Polytene chromosomes are usually found at the interphase nuclei of some tissue of the larvae of flies. Polytene chromosomes are considered to be very useful for the analysis of many facets of eukaryotic interphase chromosome organization and the genome as a whole.
Are bar eyes autosomal?
The Bar eyes mutation in fruit flies was found in genetic crosses to be inherited as an autosomal (non-X chromosome) dominant.
What causes yellow body in Drosophila?
The yellow gene (y) is involved in pattern-specific melanin pigmentation of the cuticle of the adult fly and of larval mouth parts of Drosophila melanogaster.
What does W * Mean in Drosophila?
white, abbreviated w, was the first sex-linked mutation discovered, found in the fruit fly Drosophila melanogaster. In 1910 Thomas Hunt Morgan and Lilian Vaughan Morgan collected a single male white-eyed mutant from a population of Drosophila melanogaster fruit flies, which usually have dark brick red compound eyes.
What causes white eye mutation in Drosophila?
White eye color is a mutant phenotype, caused by a mutation in a gene in the pigment pathway, discovered in 1910 by the father of modern genetics, Thomas Hunt Morgan (Green, 2010; Morgan, 1910).
What chromosome is the scarlet gene on in Drosophila?
Vermilion, a sex-linked eye color in Drosophila melanogaster (ampelophila), is duplicated in appearance by a new mutant called scarlet (symbol s1). The gene for scarlet is located in the third chromosome to the left of dich2ete.
Is Apterous fruit flies recessive?
Genetics. In traditional or Mendelian genetics, the gene for apterous flies is a recessive trait. This means that a fruit fly must get the gene for aptery from both parents.
Are vestigial wings autosomal recessive?
Vestigial wing is a recessive autosomal mutation in the fruit fly Drosophila melanogaster. Wild-type flies have red eyes, but another mutation, an X-linked recessive mutation causes white eyes. You cross a parental generation of males with vestigial wings with females that have white eyes.
What does Sexlinked trait mean?
What is Sexlinkage example?
So for the genes on the sex chromosomes, males have just one copy. The Y chromosome has few genes, but the X chromosome has more than 1,000. Well-known examples in people include genes that control color blindness and male pattern baldness. These are sex-linked traits.