Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Appl Environ Microbiol. 2012 Jun;78(12):4358-66. doi: 10.1128/AEM.00029-12. Epub 2012 Apr 6.

Diversity and expression of RubisCO genes in a perennially ice-covered Antarctic lake during the polar night transition.

Author information

  • 1Department of Medicine, University of California, San Francisco, California, USA.

Abstract

The autotrophic communities in the lakes of the McMurdo Dry Valleys, Antarctica, have generated interest since the early 1960s owing to low light transmission through the permanent ice covers, a strongly bimodal seasonal light cycle, constant cold water temperatures, and geographical isolation. Previous work has shown that autotrophic carbon fixation in these lakes provides an important source of organic matter to this polar desert. Lake Bonney has two lobes separated by a shallow sill and is one of several chemically stratified lakes in the dry valleys that support year-round biological activity. As part of an International Polar Year initiative, we monitored the diversity and abundance of major isoforms of RubisCO in Lake Bonney by using a combined sequencing and quantitative PCR approach during the transition from summer to polar winter. Form ID RubisCO genes related to a stramenopile, a haptophyte, and a cryptophyte were identified, while primers specific for form IA/B RubisCO detected a diverse autotrophic community of chlorophytes, cyanobacteria, and chemoautotrophic proteobacteria. Form ID RubisCO dominated phytoplankton communities in both lobes of the lake and closely matched depth profiles for photosynthesis and chlorophyll. Our results indicate a coupling between light availability, photosynthesis, and rbcL mRNA levels in deep phytoplankton populations. Regulatory control of rbcL in phytoplankton living in nutrient-deprived shallow depths does not appear to be solely light dependent. The distinct water chemistries of the east and west lobes have resulted in depth- and lobe-dependent variability in RubisCO diversity, which plays a role in transcriptional activity of the key gene responsible for carbon fixation.

PMID:
22492447
[PubMed - indexed for MEDLINE]
PMCID:
PMC3370527
Free PMC Article

Images from this publication.See all images (5)Free text

Fig 1
Fig 2
Fig 3
Fig 4
Fig 5

Publication Types, MeSH Terms, Substances, Secondary Source ID

Publication Types

MeSH Terms

Substances

Secondary Source ID

PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk