29 March 2012

Might we finally get a crayfish genome?

I just learned of a new project, Arthropods Genomes, which aims to sequence 5,000 arthropod genomes. The project wiki is here, which includes a form to suggest species to include for sequencing.

No need to rush. I suggested Marmorkrebs for sequencing before I started writing this post.

This should be no surprise, given that a crayfish genome is something I’ve been asking for for years. Indeed, every time someone mentions how bored they are with yet another genome being sequenced, or how hard it is for the poor genome researchers who are drowning in so much data, it’s become a running joke for me to say, “Yeah, yeah... So where’s my frickin’ crayfish genome

As of this writing, four decapod species are in the draft list. The Lousisiana red swamp crayfish, Procambarus clarkii, is on the draft list of species. This is a good choice, as we know more about its biology than probably any other crayfish.

I hope this pans out.

Related posts

Olivia’s fantasy genomes
Genome research: Good idea, bad idea
The first crustacean genome

Hat tip to Ed Yong and Alex Wild.

23 March 2012

Crayfish chemistry? Publishing error, or just added value?

Around March 19, I got an alert for a new Marmorkrebs article appearing in PubMed. It is a very interesting article about a Marmorkrebs with some male characteristics.

I was surprised by the journal, which was not one I recognized. “Biomaterials science”? Well, I suppose crayfish could be inspiration for biomaterials. I went to the link out...

Polymer edition? I was even more puzzled. There didn’t seem to be anything in the abstract about biomaterials, and especially not polymers.

One of the authors of the paper, Gerhard Scholz, confirmed that the article wasn’t supposed to be in Journal of Biomaterials Science, but Journal of Crustacean Biology. I kept watching all week for what would happen to the article.

By Friday, the article was appearing in the “Fast track” section on IngentaConnect for Journal of Crustacean Biology. The DOI for the article didn’t change.

The PubMed entry, however, still points to the polymer journal. How or when that will be updated, I don’t know, but I’ll keep checking.

This raises the question of how publishers should correct mistakes. Retraction Watch blog has a section devoted to retractions cause by “publisher error.”  Here, there has been no retraction, or notice, or explanation to the readers of Journal of Biomaterials Science - Polymer Edition. True, the error was short-lived, and the critical identifier – the DOI – was stable.

The case of the PubMed ID will be interesting to watch, because Journal of Crustacean Biology is not normally indexed in PubMed. As far as I can discover, there is only one other article (“Effect of microgravity and hypergravity on embryo axis alignment during postencystment embryogenesis in Artemia franciscana (Anostraca),” PMID: 11539283) from the journal’s history in PubMed. Whether the article will stay in PubMed, have the corrected citation information, and have the PubMed ID will stay the same, remains to be seen.

16 March 2012

German video

Some excellent crayfish photography here in this German language video interview with Gerhard Scholtz.

09 March 2012

Sintoni and colleagues, 2012

Sintoni S, Benton JL, Beltz BS, Hansson BS, Harzsch S. 2012. Neurogenesis in the central olfactory pathway of adult decapod crustaceans: development of the neurogenic niche in the brains of procambarid crayfish. Neural Development 7: 1. http://dx.doi.org/10.1186/1749-8104-7-1


Background: In the decapod crustacean brain, neurogenesis persists throughout the animal’s life. After embryogenesis, the central olfactory pathway integrates newborn olfactory local and projection interneurons that replace old neurons or expand the existing population. In crayfish, these neurons are the descendants of precursor cells residing in a neurogenic niche. In this paper, the development of the niche was documented by monitoring proliferating cells with S-phase-specific markers combined with immunohistochemical, dye-injection and pulsechase experiments.

Results: Between the end of embryogenesis and throughout the first post-embryonic stage (POI), a defined transverse band of mitotically active cells (which we will term ‘the deutocerebral proliferative system’ (DPS) appears. Just prior to hatching and in parallel with the formation of the DPS, the anlagen of the niche appears, closely associated with the vasculature. When the hatchling molts to the second post-embryonic stage (POII), the DPS differentiates into the lateral (LPZ) and medial (MPZ) proliferative zones. The LPZ and MPZ are characterized by a high number of mitotically active cells from the beginning of post-embryonic life; in contrast, the developing niche contains only very few dividing cells, a characteristic that persists in the adult organism.

Conclusions: Our data suggest that the LPZ and MPZ are largely responsible for the production of new neurons in the early post-embryonic stages, and that the neurogenic niche in the beginning plays a subordinate role. However, as the neuroblasts in the proliferation zones disappear during early post-embryonic life, the neuronal precursors in the niche gradually become the dominant and only mechanism for the generation of new neurons in the adult brain.

Keywords: None provided.