The project on which the article is based, which is directed by the expert Pat Monhagan (University of Glasgow, UK), also reveals that adult male giant petrels have shorter telomere lengths than females, a genetic difference that had not been documented until now in a scientific study of a bird species.
Telomeres, situated at the terminal end of chromosomes, are key elements in cell division. According to international research studies, telomeres shorten progressively with each cell division, and this reduction in length is associated with cell aging. The 2009 Nobel Prize for Medicine, awarded to Elizabeth H. Blackburn, Carol W. Greider and Jack Szostak, reflects the importance of the biological role of telomeres in cellular and molecular machinery.
The article in Behavioral Ecology focuses on a study of the giant petrel, a large scavenger found in the Arctic and sub-Antarctic regions which displays significant differences between males and females (size, behaviour, diet, etc), carried out in a breeding colony on Bird Island in South Georgia. “The giant petrel is a bird that can live over 50 years, making it ideal for studies of longevity”, says Dr. González-Solís, who nevertheless explains that, “It is not easy to study the effects of longevity in wild species. You need to be able to work with communities that have been extensively observed since the mid-part of the 20th century, which is the case of the colony on Bird Island, where we have been able to monitor petrels in different age groups”.
Why telomere length is different?
Male telomere length is known to be shorter in humans and in other animal species such as rats. The article in Behavioral Ecology looks at the genetic material of red blood cell samples taken from giant petrels and is the first research study to reveal differences in telomere length between males and females of the same bird species, raising the question of why telomere shortening is more pronounced in males than females. There appears to be no single explanation, although for González-Solís the different lifestyles of males and females may be one, if not the only, explanation: “There is a clear division of roles between males and females, particularly as regards feeding: males compete for the prey of seals and penguins on Antarctic beaches, whereas females feed on marine species including fish, squid or krill”. When animals have to compete for food, size is an advantage, and González-Solís explains that, “the specialized feeding strategies of males have led to an increase in body size, which raises the cell division rate and creates greater oxidative stress, hence the telomere shortening observed”. As he explains, “this is not consistent with observations in other dimorphic species such as the wandering albatross or the European shag, in which telomere length is similar between sexes”.
The difference in telomere length between males and females is also found in chicks, a finding that cannot be accounted for by lifestyle differences, since, as González-Solís explains, “At this stage the birds have not begun to display different behavioural patterns, so the different roles of males and females cannot be the only reason for the disparity in telomere lengths. In the case of chicks, perhaps it is simply that sexual dimorphism imposes different growth rates, which may promote greater telomere shortening in males. At the moment there are a number of theories and more research will be needed to work through them”.
Telomere length and bird survival
Another interesting finding of the study is the relationship between telomere length and bird survival, with those that died during the 8-year period after sampling having significantly shorter telomere lengths on average at the time of measurement. This suggests that telomere length may partially determine the life expectancy of giant petrels, independently of age and sex.
The southern giant petrel, a frequent victim of accidental capture by trawlers, is included on the Red List of Threatened Species maintained by the International Union for Conservation of Nature (IUCN). With an adult population that has fallen to 100,000, it is believed that thousands of these birds were killed inadvertently by illegal fishing vessels during the 1990s. In its future work, the team behind the study will focus on population genetics studies of colonies of giant petrels, a species with an extreme life-history strategy combining longevity and a low reproductive rate – females lay only one egg in each breeding season – that makes adults highly vulnerable to any type of survival threat.
Rosa Martínez | alfa
Newly discovered bacteria-binding protein in the intestine
08.12.2016 | University of Gothenburg
The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
08.12.2016 | Physics and Astronomy
08.12.2016 | Health and Medicine
08.12.2016 | Life Sciences