The lamprey Petromyzon marinus (P. marinus), is an agnatha (jawless) vertebrate belonging to the group of Petromyzontidae, which includes less than forty species. It has a cord, a rounded mouth with spikes, a cartilaginous skeleton and rudimentary vertebrae. Its morphology is reminiscent of that of the eel (elongated body without scales), but with a much larger size (70 cm-1 m). This species has a wide geographical distribution in Europe and North America and is easy to maintain in the laboratory during spawning periods. Oviposition is very abundant but seasonal, and embryos can be maintained in the laboratory until the prolapsed stage.

Due to the complexity of the life cycle (migratory species) and the length of the larval stages (several years), this species is not currently farmed. It is currently the reference model for cyclostomata (hagfishes and lampreys), the sister group of jawed vertebrates. This phylogenetic position makes it a key species in understanding the origin of vertebrates, and more generally, in any systematic comparative approach at the vertebrate scale. Possible functional approaches in this species include the loss of gene function via injection of morpholino antisense oligonucleotides and transient expression of reporter genes or overexpression vectors.

  • Name : Petromyzon marinus
  • Phylogenetic classification: Chordate, Vertebrate, Agnatha, Petromyzontidae
  • Genome sequencing complete since 2013 (Smith, J.J. et al, 2013)
  • Genome size : First estimates range from 1.3 to 2 billion base pairs.
    Number of coding genes: about 10.400.

Fertilization is external.

Spawning is seasonal and very abundant since a female can produce up to 10,000 eggs per clutch. The generation time is quite long, 6 to 7 years. Spawning takes place in the spring in river environments, following a spawning migration from estuaries.

Development includes an embryonic phase (6 weeks) and a larval phase (5 years), after which metamorphosis takes place followed by a return to the sea for the post-metamorphic animals.

  • BAC and EST librairies
  • Possible molecular and functional approaches: in situ hybridization, immunohistochemistry
  • Pharmacological treatments
  • Functional approaches: loss of function (injection of morpholinos at 1 cell stage)
  • Transient expression of reporter genes

Genomic databases :

EST librairy:

Database of 150 000 embyonic EST, collection of corresponding clones, available on request from S. Mazan

Development table:

The most commonly used is Tahara Y. 1988. Zoological Science 5 :109-118 (table compiled for Lampetra reissneri but also valid for P. marinus)

  • Articles

« The sea lamprey Petromyzon marinus genome reveals the early origin of several chemosensory receptor families in the vertebrate lineage. », Libants S. et al., BMC Evol Biol., 2009

« Dual nature of the adaptive immune system in lampreys. », Guo P. et al., Nature, 2009

« Modularity, comparative embryology and evo-devo: developmental dissection of evolving body plans. », Kuratani S., Dev Biol., 2009

« Neurodevelopment genes in lampreys reveal trends for forebrain evolution in craniates. », Guérin A. et al., PLoS One., 2009

« Cyclostome studies in the context of vertebrate evolution. », McCauley DW. et al., Zoolog Sci., 2008

« Ancient evolutionary origin of the neural crest gene regulatory network. », Sauka-Spengler T. et al., Dev Cell., 2007

male-enhancement-pills   penis-enlargement-medicine   best-penis-enlargement-pills   male-enhancement-pills-that-work   penis-pills   best-erection-pills   penis-enlarger   penis-enlargment   best-sex-drugs   evermax-pill   penis-enlargements   hard-on-pills-that-work   enhanced-male-pills   male enhancement   penis extender   best male enhancement pills   penis enlargement medicine   best male enhancement   penis stretcher   penis enlargement pills   extenze reviews   penis extenders   sex pills   how to produce more sperm   extenze review   extenze male enhancement   male enhancement pills that work   bathmate results   male enlargement pills   male extra   extenze pills   how to increase semen volume   increase sperm volume   penis pills   volume pills   male enhancement pills that work fast   increase semen volume   bathmate before and after   best penis enlargement pills   male enhancement pill   penis enhancement   penis pump before and after   how to increase sperm volume   best budget penis pumps   enhanced male   best erection pills   bathmate review   best penis pumps   penis traction   how to produce more cum   male enhancement products   3 ways to increase seminal fluid   male enhancement pills over the counter   penis pump results   increase ejaculate   best sex pills   male enhancement reviews   how to produce more semen   dick pills   sex pills for men   penis enlargement pill   how to increase ejaculate volume   how to increase ejaculate   extenze side effects   huge ejaculation   penis enlargement pump   water penis pump   male enhancement supplements   do penis enlargement pills work   increase semen   bath mate   penis pump reviews   penis growth pills   best male enhancement pill   bathmate routine   size genetics   male supplements   male enlargement   male extra reviews   the best male enhancement pills over the counter   how fast does extenze work   how to ejaculate more   extenze results   penile extender   bathmate x30   max performer   best penis extender   bathmate reviews   semen volume   extenze extended release   penis pumps   dick enlargement   how long does it take for extenze to work   dick pumps   penile traction   big loads   best male enhancement pills that work   increase sperm volume pills   extenze pill   best male enlargement pills   male sex pills   penis strecher   home made penis pump   dick extender   cum pills   natural ways to increase seminal fluid   best penis enlargement   penis pump before after   penile traction device   best over the counter male enhancement   over the counter male enhancement pills   male extra review   vigrx plus review   does bathmate work   extenze directions   best penis   penis enlargement pills that work   volume pill   sex pill   male enhancer   increase cum   extenze ingredients   semen volumizer   increase semen production   do male enhancement pills work   enhancement pills   vigrx pills   penis enlargment pills   stamina pills   are penis pumps safe   cock pumps   darren jackson   best natural male enhancement   penis stretchers   best penis enlargement medicine   male enhancement drugs   how to increase sperm thickness   where to buy vigrx plus   best sex pills over the counter   sexual enhancement pills   increase ejaculation   increase cum volume   sexual enhancement   penis enhancers   hard on pills that work   enhancement male pill   extenze ingridients   extenze befor and after   malextra pills   extenz results   penis enlargements pumps   extenze ingredience   male enhancement pills   penis enlargement medicines   volumepills review   penis extender result   extenze ingredient   penis pump review   how to increase ejaculation volume   cock extenders   penis enlargement devices   vigrex tablets   how to increase semen amount   male performance pills   bathmate hydro   how to increase cum load   penis extenders reviews   best male enhancers   how to increase semen production   how to produce more seminal fluid   bathmate x40   male drive max   increase cum load   bathmate before after   volume increaser   produce more sperm   best male enhancement pills over the counter   max load pills   volume pills review   natural male enhancement herbs   delay pills for men last longer   cock stretcher   enhanced male pil   male enhancement pills free trials   penispumps   penis enlargement device   male sexual enhancement   extend pills   sex enhancement pills   all natural male enhancement   long sex pill   best male supplement   extenze maximum strength   do penis pills work   produce more semen   how to produce more seminal fluid naturally   increasing semen volume   penis extenders review   how to increase semen   best male enhancement pills 2019   male enhancement pills reviews   increase ejaculate volume   bathmate hydro pump   increase seminal fluid   natural male enhancement pills   hydro penis pump   vigrx reviews   do penis extenders work   over the counter male enhancement   male enhancements   top male enhancement pills   penis traction device   bathmate pump