Sentences with phrase «sex chromosomes in»

These results demonstrate that different autosomes were involved in translocations with sex chromosomes in closely related lineages of anole lizards and that several sequential microautosome / sex chromosome fusions lead to a remarkable increase in size of Norops sagrei sex chromosomes.

But it was a surprise when researchers at Stanford University, found a few cells with Y sex chromosomes in a pregnant woman's blood in 1979; those cells had to have come from her son, since women have only X chromosomes.

For Dr. Christophe Dufresnes from the University of Lausanne, first author of the common study just published in Scientific Reports, this «suggests that the undifferentiated sex chromosomes in these tree frogs contribute more to the evolution of new species than other, normal chromosomes.»

«The gene exchange is the least between the sex chromosomes in interspecies crosses, the sex chromosomes «collaborate» the worst with the other chromosomes from the foreign species,» he says.

Later, a different group found that the sex chromosomes in the jammed - together leftovers were always of the XX variety — female — regardless of the devil host's gender.

The X and Y sex chromosome in most mammals began to diverge after 160 million years of evolution.

Not exact matches

(Side note to everybody everywhere who talks about this ever: Sex is biological, as in male and female and X and Y chromosomes.

In a preliminary experiment, the team found that stem cells produced from fibroblasts of men with Klinefelter syndrome also lost the extra sex chromosome.

They turned the fibroblasts into stem cells and noticed that in the process, some of the cells lost the extra sex chromosome.

Third place honors and $ 150,000 went to Isani Singh, 18, of Aurora, Colo., for her work toward determining if women with Turner syndrome, a rare disease in which all or part of a woman's second sex chromosome is missing, may have some cells with two X chromosomes.

In colder climates, these aphids start producing male clones (which are identical to the mother except they lack a sex chromosome).

For birds, the sex chromosome passed mother determines the sex of the offspring, the reverse of how it works in all mammals.

The SRY (sex - determining region Y) gene on the male's Y chromosome orchestrates the formation of the testes, while the gonadal precursor will differentiate into an ovary by default (in the absence of the steroids produced by the testes).

«The next step will be to discover which gene on the Y chromosomes determines sex in the platypus and echidna.

University of Adelaide School of Molecular and Biomedical Science PhD student, Deborah Toledo - Flores, says: «the most important aspect of this work for us was to identify more genes on platypus Y chromosomes to reveal new leads about potential sex determining genes in these animals.»

It finally reveals the gene content of the two different Y chromosome systems that evolved in mammals,» says Dr Grützner, who has led research into monotreme sex chromosomes for more than 10 years.

Typically, a worm's sex - determination — in this case, making eggs or sperm — comes down to counting chromosomes.

The Y chromosome is only found in males and plays a key role in determining male sex.

While it did nothing to calm the maelstrom swirling around Summers, the new understanding of the chromosome revealed tantalizing clues to the role genes might play in shaping cognitive differences between the sexes.

But in a separate study, geneticist David Page of the Whitehead Institute at MIT and his colleagues found that the chimp Y, the male sex chromosome, contains debilitating mutations in a number of genes.

Research in mice has found a way to make fertile sperm from animals born with too many sex chromosomes.

In mosquitoes, as in humans, the sex - determining chromosomes are X and In mosquitoes, as in humans, the sex - determining chromosomes are X and in humans, the sex - determining chromosomes are X and Y.

Like others before him, Schrödinger was struck by the fact that chromosomes are accurately duplicated during ordinary cell division (mitosis, the way in which an organism grows) and during the creation of the sex cells (meiosis).

During the formation of eggs and sperm, the cell's chromosomes must pair up and part in an elaborate sequence that results in sex cells with exactly half the number of chromosomes as the parent cell.

But just how the birds manage to change that ratio remains a mystery: Sex in birds is determined by which chromosome the egg carries, and each egg starts out with a 50 - 50 chance of being male or female.

The findings, published online this week by the Proceedings of the National Academy of Sciences, provide the strongest evidence to date in support of the notion that sex chromosomes acting on single cells play a role in differences between male and female brains.

As a result, these sex chromosomes have basically no time to degenerate as in mammals.

Indeed, this point seems to have already been passed in the tree frogs in Poland, their sex chromosomes can no longer easily admix.

In many animals sex is determined by sex chromosomes.

The finding suggests that the W chromosome is not crucial to determining sex in bearded lizards.

Among its oddities: 52 chromosomes, including 10 sex chromosomes, as well as the highest number of repeated segments in the genome of any mammal sequenced so far.

The popular knowledge on sex chromosomes usually considers the situation in mammals, in which sex chromosomes are easily distinguishable under the microscope.

«Developing a new tool to detect a frequently missed sex chromosome disorder in boys.»

In this little fish, researchers can observe the development of sex chromosomes which occurred in mammals 300 million years agIn this little fish, researchers can observe the development of sex chromosomes which occurred in mammals 300 million years agin mammals 300 million years ago.

In nearly all Lepidoptera — the order that includes moths and butterflies — sex is determined by a WZ chromosome system, in contrast to the XY system used in mammalIn nearly all Lepidoptera — the order that includes moths and butterflies — sex is determined by a WZ chromosome system, in contrast to the XY system used in mammalin contrast to the XY system used in mammalin mammals.

«Either temperature - dependent sex determination, or sex chromosomes, usually determined the development of genitalia in snakes and lizards.

The issue of sex is particularly acute in preclinical studies of Rett syndrome, a disorder caused by mutations in a gene located on the X chromosome.

The discovery marks the latest in a series of findings related to the protein SRY (sex - determining region on the Y chromosome), which serves as a master switch for ensuring typical human male maturation.

Scientists worry that although there hasn't been an obvious increase in birth defects so far, sex chromosome abnormalities may show up when the children reach puberty.

Both the Z chromosome and this X chromosome seem to have a gene called DMRT1, which in birds is likely the sex - determining gene; that is, the gene that helps steer a developing bird embryo toward one gender or the other.

Now researchers have found even more strangeness in how the sex chromosomes behave during the cell cycle.

It's not clear how that may have happened, because large deviations in the amount of DNA usually kills fetuses or renders them infertile because of abnormalities in the amounts of various proteins produced or because organisms can not tolerate having extra copies of sex chromosomes.

According to their model, multiple translocations deposited the two sex determinants on the same chromosome, with a centromere in between.

In the 1960's, Japanese - American geneticist and evolutionary biologist Susumu Ohno proposed a theory in which the genes determining sex first arose at various spots scattered across the entire genome, but over time were «captured» on the sex chromosomeIn the 1960's, Japanese - American geneticist and evolutionary biologist Susumu Ohno proposed a theory in which the genes determining sex first arose at various spots scattered across the entire genome, but over time were «captured» on the sex chromosomein which the genes determining sex first arose at various spots scattered across the entire genome, but over time were «captured» on the sex chromosomes.

The toddler in the study had a mutation in the gene encoding SRY, or sex - determining region of the Y chromosome, a protein that initiates testes development in embryos.

In this study, researchers analyzed the evolutionary mechanism of sex chromosomes, and reported that the alligator was the first TSD species whose genome has been sequenced, which will have great implication in resolving sex chromosome evolutioIn this study, researchers analyzed the evolutionary mechanism of sex chromosomes, and reported that the alligator was the first TSD species whose genome has been sequenced, which will have great implication in resolving sex chromosome evolutioin resolving sex chromosome evolution.

Sex chromosomes and hormones appear to have a role in this, but the full reason is uncertain.

In this configuration, the chromosomes are ordered by length from the largest (chromosome 1) to the smallest (chromosome 22 in humans), followed by the sex chromosomeIn this configuration, the chromosomes are ordered by length from the largest (chromosome 1) to the smallest (chromosome 22 in humans), followed by the sex chromosomein humans), followed by the sex chromosomes.

Unlike all other chromosomes in our cells, the Y chromosome, which bears the male sex - determining gene, is passed essentially unchanged from father to son, barring rare mutations.

One possible biological problem with males focuses on genetics, and in particular the sex chromosomes.