Quetzalandia - SCIENCES

ANIMALS GENOME SEQUENCED:

Scientists have sequenced the genome of the honey bee, which has given new insights into its African origin, the evolutionary transformation it has undergone and its capabilities of memory, language and evolving a hierarchical system.

The Honeybee Genome Sequence Consortium, which undertook the research (costing $7.6 million and starting in 2003), reports about what is describes a social revolution "encoded subtly" within a genome possessing more than 10,000 genes. The findings of the study are reported in the latest issue of the journal Nature.

While extensive studies have been done on the social structure followed by honey bees and on the hierarchical system where the queen bee is the center, surrounded by the male drones capable of reproduction and the female worker bees, which are responsible for food gathering, defense and house-keeping, there has been little knowledge on the genes that created such diverse behavior in the inhabitants in the same hive, their memory powers and the ability to use language...

The study finds that bees have many genes for detecting odors but relatively few for taste receptors or immunity. Bits of RNA appeared to show different on-off patterns whether they are in queens or workers, hinting at a mechanism for retaining social standings.

The researchers also say as the evolution happened, honeybees gained a memory power to identify where nectar sources are and an ability to communicate the relative distance and direction of these sources with a "waggle dance." The researchers describe this as symbol language yet to be related to species beyond the primates.

A group among the scientists also used genetic variations among different honeybee subspecies to determine that the Apis mellifera lineage came from Africa and not Asia, as believed earlier, and spread to Europe and Asia through migrations.

The researchers have identified a 100-million-year-old amber-encased bee. One of the co-authors of the study, Bryan Danforth, an entomologist at Cornell University, said the tiny insect may well fill in a family tree that now contains about 16,000 species.

The new genetic information gleaned from the studies may not explain outright how the bees became social animals, how they developed memory and how they came to use language, but by comparing the genome with those of the other two insects that have been sequenced -- the fruit fly and a mosquito -- there will be possible conclusions, the scientists feel.

The researchers estimate that bees have around 10,000 genes, compared with 25,000 in humans and 14,000 in mosquitoes.

eneticists have published the full genetic code of a 12-year-old boxer. There are more than 400 dog breeds, distinguishable from each other by millions of small differences that are clustered in blocks within the animal's genetic code. These genetic differences are a useful tool for understanding how complex traits in dogs have evolved.,,

Ever since the release of the human genome, new species have been sequenced at regular intervals. Sequenced species include representatives of mammals, fish, invertebrates such as Caenorhabditis elegans and insects, and single-celled organisms. So, is the chicken only 'yet another genome'? No, this is indeed a special one, and the new results have several important and novel implications. Most notably, it is the first sequenced bird genome. The significance of this may not be obvious to the casual reader, but this will allow new detail in understanding human evolution. Earlier genomes sequenced are either considered to be too evolutionarily remote from man – such as C. elegans and Fugu – or too close – mammals such as mice and rats – to offer proper understanding of genome development. A bird is just on the right phylogenetic distance – the common ancestor of birds and mammals dating about 300 million years back – for getting to grips with evolutionary histories of genome structure and function, such as evolution of karyotypes, relation between expressed and non-expressed parts of the genome or gene conservation...

The first animal genome sequence
In December 1998, the complete 100Mb genome sequence of the nematode worm Caenorhabditis elegans was reported. This was the outcome of a long-standing international collaboration between the Sanger Centre in Cambridge and the Genome Sequencing Center at Washington University, St.Louis. The work started in the mid-1980s with the pioneering work in constructing a physical map of the genome using overlapping 40kb bacterial clones (cosmids) which were assembled into larger contiguous regions (contigs). Gaps between bacterial clone contigs were bridged using larger nematode genomic fragments cloned into an alternative cloning system using yeast as the host (yeast artificial chromosomes, or YACs), resulting in a complete map of the six nematode chromosomes with only two unclonable gaps. The entire sequence of the C. elegans genome was then determined from a set of overlapping clones (or tiling path) selected from the physical map. Each clone was taken through an initial shotgun sequencing phase, in which about 1,000 random individual sequences, or "reads", were assembled into a consensus and released on the internet. Following this, a second phase, of directed finishing, was carried out to close any remaining gaps, resolve all ambiguities and to check every base. The resulting "finished" sequence has a minimum accuracy of 99.99%. Analysis of the finished sequence resulted in identification of 19,000 genes, and 26% of the encoded proteins were found to have counterparts (homologues) in yeast. In broad terms, this reflects the cellular functions that are common to yeast, a unicellular eukaryotic organism, and the nematode, which is made up of eukaryotic cells. Many of the nematode genes without homologues in yeast encode proteins that are involved in features of the multicellular animal - specialisation of cells to perform different functions, interactions between cells in the body, the programmed growth and development of the animal, and processes such as feeding and movement...

Researchers from the Bovine Genome Sequencing Project recently announced the release of a comprehensive set of genome resources into freely available public databases. These new assets for bovine researchers include the most complete and accurate genome sequence to date, an upgraded genetic map, and a new set of two million DNA base differences for use as DNA sequence polymorphisms...

Similarities Found in Mouse Genes and Human's

An analysis of the mouse genome by an international consortium of
scientists, a landmark event in biology, shows it is so similar to that of people that
it should speed efforts to understand the human genome and the genetic roots
of disease.

This is the first time that the reasonably complete genomes of two mammals,
mouse and man, have become available for comparison. While the genome of a
mammal even closer to the human, like the chimpanzee, may someday be decoded,
the mouse is both genetically close and also an ideal laboratory animal.

Man and mouse are cousins, each descended from a small mammal that split
into two species toward the end of the dinosaur era. Despite 75 million years of
separate evolution, only about 300 genes - 1 percent of the 30,000 possessed
by the mouse - have no obvious counterpart in the human genome, according to
the new analysis published in today's issue of Nature.

This similarity makes the mouse genome an excellent surrogate for studying
the human genome, especially for tests that would be ethically impossible in
people. To understand the role of any newly found human gene, researchers can
identify the counterpart gene in mice, genetically engineer a strain of mouse
that lacks the gene, and figure out from the mouse's defects what the
missing gene is meant to do.

The analysis has also yielded new insight into the workings of evolution and
brought to light the existence of a large class of novel genes that produce
a substance related to DNA.


IMAGES	BIOTECNOLOGY	MATH	NEUROSCIENCES	OTHERS
NEURONS IMAGES	Human Genome Project	MATH PROBLEMS	Neurosciences Stuff	BRAIN BOOTS
Diagrams of Biotech			Clips on Neurosciences	Cloning a Yeast Artificial Chromosome diagram

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