RATIFICATION PAGE

Complete report of Genetics & Evolution with the title is “ Giant

Chromosome”, which made by :

name : Syaiful Bakhri

reg. no : 081 404 192

group : III

Have been checked and consulted by Assistant and Assistant Coordinator and

this report is accepted.

Makassar, December 3th, 2010

Assistant Coordinator,

Misnawati S.Si

Assistant,

Djumarirmanto S.pd

Known by

Lecturer of Responsibility,

Hartati, S.Si, M.SiReg No : 1974040520000032002

CHAPTER IINTRODUCTION

A. Background

Genetics is already on the heritage and diversity characteristics of an

organism, whether it is unicellular and multicellular organisms. Research in the

field of genetics have been analyzed for the level monocular ribonucleic acid

(DNA) is a chemical substance that builds a chromosome as a substance which

fell. Most which has been discovered about the molecular structure of DNA and

also replication. Each unicellular and multicellular organisms have a somewhat

different form in terms of both size and composition, but all fixed chromosomes

were prepared by the DNA. Chromosome contained in each cell primarily in the

nucleus of a cell organism. Chromosomes can be observed with a microscope

with a magnification tool that is certain. Chromosome-chromosome derived from

the female parent male-like shape of so-called homologous chromosomes pair and

the number of cells in the body called the diploid (2n), sex cells contain only half

the number of chromosomes found in cells somatic limiting the number of

chromosomes is called haploid.

Chromosomes derived from the female parent with a similar shape from

male parent. Then a pair of chromosomes are called homologous chromosomes.

Therefore in body called diploid chromosome number (2n). sex cells (gametes)

contain only half the chromosomes found in somatic cells. Because the number of

chromosomes in gametes is called the haploid (n). single cell from a species

namely haploid genome. The number of chromosomes possessed a variety of

creatures never an equal. But the number of chromosomes possessed every living

thing in general does not change during his life. As human beings and cattle 46

chromosomes 60.

In order to better understand the structure and can saw firsthand that there

are giant chromosomes in fruit flies (Drosophila melanogaster), the practicum is

held. With fruit fly larvae use estimated at instars phase three we can see the

structure of the giant chromosome.

B. Purpose

This practicum aimed to observe the giant chromosome contained in the larval fruit fly (Drosophila melanogaster).

C. Benefit The benefit of this lab is, students can learn how to make fresh

preparations of the salivary gland cells of fruit flies, and can observe the light

Drosophila melanogaster chromosome.

CHAPTER IIPREVIEW OF LITERATURE

In addition to increasing the volume of the cell's nuclei and causing cell

expansion, polytene cells may also have a metabolic advantage as multiple copies of

genes permits a high level of gene expression. In Drosophila melanogaster, for

example, the chromosomes of the larval salivary glands undergo many rounds of

endoreplication, to produce large amounts of glue before pupation. Polytene

chromosomes have characteristic light and dark banding patterns which can be used

to identify chromosomal rearrangements and deletions. Dark banding frequently

corresponds to inactive chromatin, while light banding is usually found at areas with

higher transcriptional activity. The banding patterns of the polytene chromosomes of

Drosophila melanogaster were sketched in 1935 by Calvin B. Bridges, in such detail

that his maps are still widely used today. The banding patterns of the chromosomes

are especially helpful in research, as they provide an excellent visualization of

transcriptionally active chromatin and general chromatin structure( Anonyma,2010)

Polytene chromosomes are found in the salivary glands malpighian tubules,

gut, etc. of Drosophila and Chironomuslarva. These chromosomes show swellings

here and there. These swellings of double Polytene chromosomes are called puffs or

balbiani rings.The study of puffing pattern offers the following conclusion:

1. Puffs are the regions of gene activity. in the puffs mRNA transcription occurs

actively.

2. The positions of puffs are different in different tissues at any one timeChanges

in puffs of giant chromosomes of Drosophila hyder salivary during

development.

3. The positions of puffs are different in the same tissue at different stages of

development.

4. At any one time, all the cells of any one tissue show the same pattern of

puffing.

5. A particular puff produces a particular type of protein. (Anonymb,2010)

During the early period of genetics, the search for mutants was a slow, tedious

procedure dependent on the spontaneous appearance of altered genes, In 1927, using

a special strain of fruit flies designed to reveal the presence of recessive alleles, H.J.

Muller found the files subjected to a sublethal dose of X-rays displayed more than

100 times nthe spontaneous mutation rate exhibited by nonirradiated controls. This

finding had important consequence. On the practical side, the use of mutagenis

agents, such as X-rays and ul;traviolet radiation, greatly increased the number of

mutant available for genetic research. The finding also pointed out the hazard of the

increasing use of radiation in the industrial and medical fields. Today, mutation in

Drosphilla melanogaster are most often generated by adding a chemical mutagen

( ethyl methane sulfonate ) to the animals feed (Gerald,1987)

A second type of giant chromosome. Occurs in the mid-prophase of meiosis

in the oogenesis of certain animals. OOcyte nuclei are almost always large, and

perhaps especially so in groups with yolky eggs. It is apparently when such nuclei

occur in species with high DNA values thet we are apt to get giant chromosome of

the ‘lampbrush’ type-so called from their imagined resemblance to the brushes used

to clean old fashioned oil-lamp chimneys. It is fairly clear, however, that these

chromosome do not really constitute an entirely distinct type, but are merely extreme

examples of the more usual type of mid prophase chromosome in oogenesis

(Edward,2005).

Structure of these ‘ giant chromosome’ and their relationship to regular

mitotic chromosome but the “polytene hypothesis” originally proposed by Koltzoff

(1943) and modified buy Bauer (1953), is now fully accepted ( Bauer and Beerman,

1952; Beermann (1962) may be consulted for a complete consideration of the

evidence as the following is only a brief account. Polytene chromosome developed

from the chromosome of diploid nuclei by successive duplication of each

chromosome element. Usually the homologous chromosome pair early during this

process and remain paired throughout polytenization. The chromosome duplication

involved differs from that typical of a normal mitotic cycle in many respect. The

homologues remain paired . the chromosome fail to participate in the normal mitotic

cycle of coiling remain intimately paired with each other at the end of each

replication cycle and the nuclear membrane and nucleoli remain intact throughout the

replication cycles (Beament, 2007).

The chromosomal locations of several satellite DNAs have been determined

by a technique called in situ hybridization. It involves annealing single strands of

isolated radioactive satellite DNA directly to denatured DNA in chromosome squash

preparation. After washing out the non hybridized radioactive material, the location

of the satellite DNA sequences in chromosome determined by autoradiography.

Satellite DNA are usually in heterochromatic regions of the chromosomes, of the

around centromeres and nearstelomeres, and are not transcribed into RNA. Other

kinetically distinguished classes of DNA are they moderately repetitive and unique

DNA (Pragya,1989).

In the following we describe first the principle of the classic approach to gene

localization as introduced by Morgan and his followers. This provides an opportunity

to introduce some general concepts. We then discuss statistical methods for detecting

and measuring linkage in humans. The various groups of DNA markers are describe

next, followed by the principle of cell fusion and its use in localizing genes on

chromosomes, as well as the application of radioactive and no isotopic in situ

hybridization for this purpose. Genetics maps are compared to physical maps. And

the use of linkage studies as analytical tools in genetic analysis of common diseases

with complex etiology and pathogenesis (Vogel, 1954).

The formation of giant chromosome is characterized by marked variations in

the degree of the chromosome close attachment : from a complete association of

chromosome along the entire length of the chromosome in suspensor to a local

attachment in heterochromatic areas of the antipodes and ceelsa of the haustorium . In

the antipode cells for instance, several nuleus types are described those with

despiralized chromosome bound in heterochromatid block areas, those with many

decondensed isolated chromatin fibrils, those with separately located

endochromosomes and those with giant chromosome in which the chromatids are

attached to each other along almost the entire chromosome length (kwang.1989).

CHAPTER IIIMETHODE PRAKTICUM

A. Time and Place

Day / Date : Friday / November 26th 2010

Time : 13.00 a.m. until 15.00 a.m.

Place : Biology Laboratory IInd floor West FMIPA UNM Makassar

B. Tool and Material

1. Tools

a. Electron microscope

b. Light Microscope

c. Object glass

d. Deck glass

e. Razor blade

f. Bunsen

g. Pipette

2. Materials

a. Physiological NaCl

b. Instars of fruit flies (Drosophila melanogaster)

c. Asetokarmin

C. Work procedure

1. Choosed the larvae are large, then dripped glass preparations with

physiological NaCl.

2. Flies that have been drugged take slowly by using tweezers and then save in a

petri dish.

3. Dissected instar on preparations glass then dissect the head.

4. Dripped with asetokarmin

5. Closed with a deck glass and then pressed.

CHAPTER IVOBSERVATION RESULT AND DISCCUSSION

A. Observation result

Giant Chromosome Notes :

1. Chromosome

2. Centromer

3. Arm

B. Discussion

In the results as observed in Drosophila melanogaster, in which the anterior

part of larval salivary glands have to be observed how the shape of giant

chromosomes contained therein. Before making observations under the microscope

first salivary glands that have been taken in the anterior part of larvae is pressed with

glass objects for the salivary glands can glass or destroyed, so that the cells spread to

facilitate the observation. In addition, fresh preparations were poured with

asetokarmin then by using Bunsen. The purpose is to clarify the provision

asetokarmin chromosome. While aiming to preparate fixation performed on the glass

object.

Typical of giant chromosomes are there handcuffs, ribbon and bright gsri

regularly arranged alternately. Ribbon light on this chromosome is eukromatin with

winding tenuous. While the dark band is winding heterokromatin with a solid and can

undergo condensation. DNA is generally found in dark bands. The part that plays an

active role in the division is part of the ribbon to kromsom X, 1032 krmosom ribbon

on the second, 1047 the ribbon on the third chromosome and 34 on chromosome band

on the fourth chromosome. So the total is 2650 to ribbon one genome. In several

studies mentioned that the number of tape is 3286.

Giant chromosomes of Drosophila melanogaster is an interphase

chromosome and more elongated than metaphase chromosomes. Because they can be

viewed at the time of interphase chromosomes, while not unusual, because they are

the result of repeated duplication of krmosom without cell division. Homologous

duplication duplication-both paternal and internal location perfectly side by side.

CHAPTER VCONLUSSION AND SUGESSTION

A. Conclusion

Based on the observations we can conclude that the giant chromosomes are

chromosomes found in Drosophila melanogaster salivary glands, which has a

structure that is larger and longer than normal body chromosomes.

B. Suggestion

a. For Laboratory

1. Laboratory should prepare complete equipment and materials which will be

use in practicum, so easy for practicant to done the practicum.

2. Laboratory should complete the practicum rooms with air conditioner or

fan so make practicant glad to be in laboratory.

b. For Practicant

1. Practicant should prepare anything they need before enter into laboratory,

so they will easy to done practicum.

2. Practicant should work together with teammate, so practicum will be

faster and the result.

BIBLIOGRAPHY

Anonyma.2010.Giant chromosome. http://en.wikipedia.org/wiki.

Anonymb. 2010. giant chromosome http://www.unjabisnis.com/2009/12/\sex influence gene \.html

Edward willets.2005. Genetic demystified. New York : MC Graw hill

Gerald karp 1987,cell and molecular biology. New York: brooks Cole

J.W.L. Beament.2007. Advances in insect physiology. New York: Humana Press

Kwang w. jeon.1989.international review of cytology. New York: Academic press

Pragya.khanna.1989.essentials of genetic. New York: Greenwood publishing group

Vogel and motulsky’s.1954.human genetic. New York: Academic Press

anonyma

Polytene chromosomeFrom Wikipedia, the free encyclopediaJump to: navigation, search

Polytene chromosomes in a Chironimus salivary gland cell

Polytene chromosome

Polytene chromosomes from Axarus larva

To increase cell volume, some specialized cells undergo repeated rounds of DNA replication

without cell division (endomitosis), forming a giant polytene chromosome. Polytene chromosomes form when multiple rounds of replication produce many sister chromatids that remain synapsed together. Polytene chromosomes were originally observed in the larval salivary glands of Chironomus midges by Balbiani in 1881.[1]

In addition to increasing the volume of the cell's nuclei and causing cell expansion, polytene cells may also have a metabolic advantage as multiple copies of genes permits a high level of gene expression . In Drosophila melanogaster , for example, the chromosomes of the larval salivary glands undergo many rounds of endoreplication , to produce large amounts of glue before pupation .

Polytene chromosomes have characteristic light and dark banding patterns which can be used to identify chromosomal rearrangements and deletions. Dark banding frequently corresponds to inactive chromatin, while light banding is usually found at areas with higher transcriptional activity. The banding patterns of the polytene chromosomes of Drosophila melanogaster were sketched in 1935 by Calvin B. Bridges , in such detail that his maps are still widely used today. The banding patterns of the chromosomes are especially helpful in research, as they provide an excellent visualization of transcriptionally active chromatin and general chromatin structure.

Chromosome puffs are diffused uncoiled regions of the polytene chromosome that are sites of RNA transcription. A Balbiani ring is a large chromosome puff.

Polytene chromosomes were originally observed in the larval salivary glands of Chironomus midges by Balbiani in 1881, but the hereditary nature of these structures was not confirmed until they were studied in Drosophila melanogaster in the early 1930s by Emil Heitz and Hans Bauer. They are known to occur in secretory tissues of other dipteran insects such as the Malpighian tubules of

Sciara and also in protists, plants, mammals, or in cells from other insects. Some of the largest polytene chromosomes described thus far (see scale bar in figure below) occur in larval salivary gland cells of the Chironomid genus Axarus.

Another form of chromosomal enlargement that provides for increased transcription is the lampbrush chromosome.

Polytene chromosomes are also used to identify the species of Chironomid larvae that are notoriously difficult to identify. Each morphologically distinct group of larvae consists of a number of morphologically identical (sibbling) species that can only be identified by rearing adult males or by cytogenetic analysis of the polytene chromosomes of the larvae. Karyotypes are used to confirm the presence of specific species and to study genetic diversity in species with a wide range.[2][3]

Anonymb

Puffing Pattern in Polytene ChromosomesPolytene chromosomes are found in the salivary glands malpighian tubules, gut, etc. of Drosophila and Chironomuslarva. These chromosomes show swellings here and there. These swellings of double Polytene chromosomes are called puffs or balbiani rings.

The study of puffing pattern offers the following conclusion:1. Puffs are the regions of gene activity. in the puffs mRNA transcription occurs actively.2. The positions of puffs are different in different tissues at any one time

Changes in puffs of giant chromosomes of Drosophila hyder salivary during development.

3. The positions of puffs are different in the same tissue at different stages of development.4. At any one time, all the cells of any one tissue show the same pattern of puffing.5. A particular puff produces a particular type of protein.

Puffing is induced by ecdysone,  metamorphosis. When this hormone is injected into the larva in the last instar stage (this instar converts the larva into pupa), the larva develops puffing pattern similar to that develops during pupation. The puffing pattern clearly demonstrates that only a particular set of genes are made active in a tissue a particular time.