Tag Archives: allan spradling

Insect Glands May Illuminate Human Fertilization Process

Baltimore, MD — Insect glands are responsible for producing a host of secretions that allow bees to sting and ants to lay down trails to and from their nests. New research from Carnegie scientists focuses on secretions from glands in the reproductive tract that help sperm survive and guide the sperm on the trip to fertilize an egg. The gene that controls the development of these glands in fruit flies provides important information about gland development in all insects, as well as potential clues to similar human reproductive glands. Their work is published this month in Current Biology.

When a female fruit fly receives sperm from a male fruit fly, lubricating secretions in her reproductive tract activate the sperm, store it, and guide it to fertilization. Without the aid of these secretions, sperm would not make it to the eggs. Carnegie’s Allan Spradling and Jianjun Sun demonstrated that the gene in charge of regulating the development of fruit fly secretion glands is called Hr39. It encodes a steroid receptor protein. (more…)

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A “Jumping Gene’s” Preferred Targets May Influence Genome Evolution

Baltimore, MD — The human genome shares several peculiarities with the DNA of just about every other plant and animal. Our genetic blueprint contains numerous entities known as transposons, or “jumping genes,” which have the ability to move from place to place on the chromosomes within a cell.

An astounding 50% of human DNA comprises both active transposon elements and the decaying remains of former transposons that were active thousands to millions of years ago before becoming damaged and immobile. If all of this mobile and formerly mobile DNA were not mysterious enough, every time a plant, animal or human cell prepares to divide, the chromosome regions richest in transposon-derived sequences, even elements long deceased, are among the last to duplicate. The reason for their delayed duplication, if there is one, has eluded biologists for more than 50 years. (more…)

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