The female orgasm has been a topic of debate among evolutionary biologists (and among many other people as well, of course). Is it adaptive, or a by-product of the male orgasm? Does it suck sperm into the uterus, or strengthens the pair bond? Or did it ‘tag along’ with the development of the male orgasm?

A new study, published in Animal Behaviour, takes a look at the question. The authors argue that, if the female orgasm is an evolutionary by-product, similar genes would lie at the root of orgasmic function in both sexes. Consequentially, opposite-sex twins and siblings would share more similarities in their susceptibility to orgasm.

Some viruses change the behavior of their host, notable examples being the zombie ants and cat-loving rodents. Another example of such a ‘mind-controlling’ virus is the baculovirus, controlling its host, the gypsy moth caterpillar. A new study has identified a single gene that enforces this control on its host.

Jumping genes, or more technically, transposons (see figure 1), are sequences of DNA that can move around the genome and find themselves a new place. In eukaryotic DNA, these jumping genes can constitute a sizeable portion of the genome (up to 50% of the human genome is made up out of active transposons and the remains of former ones that became inactive).

Figure 1: General structure of a transposon.

(Source: Scitable, by Nature Education)

Beyond being a mystery in themselves, these bits of moving DNA (and their remnants) are remarkably prevalent in chromosome regions that are the last ones to replicate.

What is the origin of bird digits? This question has caused a lot of head-scratching and beard-stroking in evolutionary biologists. Paleontological evidence suggests that the three digits in birds develop from digit position 1, 2 and 3 (thumb, index and middle finger). Embryological evidence points towards digits 2, 3 and 4 (index, middle and ring finger). Vertebrates are ‘programmed’ to develop five digits on each limb, but there are exceptions. Such as birds, which have three. But which three?

A new study, published in Science, describes a multi-gene synthetic circuit that can distinguish between cancer and non-cancer cells, after which it can target the cancer cells for destruction. Through recognizing five intracellular cancer-specific molecules, the circuit is able to accurately identify cancer cells, which, after detection, are destroyed.

Finding the right combination of molecules was challenging. Looking among microRNA molecules, which are post-transcriptional regulators, the researchers were eventually able to find one miRNA combination that was typical for HeLa, or cervical cancer, cells. The combination is made up out of five specific miRNAs, and is sufficient to identify HeLA cells among healthy cells (see figure 1).

As the genome sequencing technologies progress, and the costs per genome sequenced go down, the number of genomes sequenced increases. So far, several hundreds of genomes have been sequenced, with many more on their way. Now, the first lizard genome has been sequenced. The genome of the green anole (Anolis carolinensis) is the first non-bird reptile genome sequenced, and, as such, an important ‘gap’ in the vertebrate genome record is beginning to be filled.

Already, some interesting observations have been made.