Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Occurence of foraminifera and other microfossils in sediment core CRP-2/2A (Table 1)

Sparse to moderately abundant foraminiferal assemblages from Oligocene and Lower Miocene sediments in the CRP-2/2A drillhole contain C.27 genera and 42 species of calcareous benthic foraminifera. No planktic or agglutinated taxa were observed. On the basis of their faunal characteristics, four Foraminiferal Units are defined in drillhole succession: Foraminiferal Unit I (26.91-193.95 mbsf), mostly sparse assemblages with Elphidium magellanicum and Cribroelphidium sp.; Foraminiferal Unit II (193.95-342.42 mbsf), mostly moderately abundant assemblages with Cassidulinoides aequilatera and Eponides bradyi; Foraminiferal Unit III (342.42-486.19 mbsf), moderately abundant to sparse assemblages characterised by Cassidulinoides chapmani and Stainforthia sp.; and Foraminiferal Unit IV, Improverished (486.19-624.15, total depth, mbsf), with mostly barren residues, but with large Milioliidae recorded in situ at various horizons in the drill core. Foraminiferal Units I-IV lack taxa allowing correlation to standard zonal schemes. Inspection of faunal records from CIROS-1 and DSDP 270 indicates that, although the faunas show an overall similarity, CRP-2/2A Foraminiferal Units I-IV are not identifiable at these sites. The units are therefore most likely to reflect local environmental changes, and probably will prove useful for local correlation, but their lateral extent is undetermined. All four assemblages apparently represent various glacially-influenced shelf environments, and appear to reflect a long term deepening trend from Units IV to II, from perhaps inner to mid or outer-shelf depths, followed by a return to shallower, inner shelf, conditios for Unit I

(Table 1) Distribution and numerical abundance of foraminifera of sediment core CRP-3

A foraminiferal fauna comprising c. 33 genera and c. 53 species was recovered from a suite of 156 Lower Oligocene sediment samples, mostly muddy sandstone and siltstone, selected over the 2.80 - 823.11 mbsf depth range in the CRP-3 drillhole. All foraminifers, except for 2 isolated specimens, occurred above 340 mbsf, with 54 of 103 samples from above this depth being fossiliferous. At a generic and even a specific level, the fauna contains many components for the present-day Antarctic foraminiferal biota, indicating that its origin is at least as old as early Oligocene. Foraminiferal assemblages represent a single biofacies which is characterised by low diversity, and by dominant and persistent occurrences of Cassidulinoides chapmani, other Cassidulinoides and Globocassidulina species, and Stainforthia sp. These taxa and commonly accompanied by Cibicides lobatulus, Epistominella exigna, Fissurina spp. Nonionella spp., and Oolina spp. Large miliolids occur as isolated specimens at various levels. Planktic species are absent, and agglutinated taxa occur only rarely and sporadically. Preservation generally is fair good, while absolute abundance is very low, with a maximum of c. 6 specimens/gram, and most samples containing <1 specimen/gram. These assemblages probably represent mid to outer shelf depth (50-200 m) in glacially influenced environments with a high sedimentation rate and poor oceanic connections. Although the CRP-3 fauna closely resembles the one from Foraminiferal Unit III as defined in CRP-2/2A (CRP-2/2A Science Team, 1999; Strong & Webb, 2000, hdl:10013/epic.28260.d001), absence of some species, and the first records of others in the uppermost CRP-3 section, is consistent with an interpretation of minimal overlap between the CRP-2/2A and CRP-3 sediments. The fauna also appears correlative with the Globocassidulina-Cassidulinoides-Trochoeiphidiella Assemblage Zone from lower DSDP-270, and with faunas from the lower but not lowermost, section at CIROS-1

Investigation of Miocene foraminifera in sediment core CRP-1 from the Ross Sea, Antarctica

A faunal comprising 18 foraminiferal taxa wa recovered from a suite of 52 core samples from lower Miocene sandstone, claystone and diamictite in the CRP-1 drillhole, Cape Roberts, Antarctica. The fauna is characterised by low foraminiferal abundance and diversity, the absence of planktics, and typically, the presence of Cribroelphidium sp. and/or Melonis spp. These factors indicate deposition in an inner shelf or nearshore environment. Many of the foraminifers found in CRP-1 also occure in the upper Oligocene-Miocene sequences in CIROS-1 and DSDP-270, but the fauna provides no precise indication of age. Typical and distinctive species from CRP-1 are illustrated with SEM photomicrographs

Investigation of Quaternary foraminifera in sediment core CRP-1 from the Ross Sea, Antarctica

Foraminifera are examined in twenty-six samples from a 44 metre succession of Quaternary glacial sediments recovered from the CRP-1 drillhole on Roberts Ridge, southwestern Ross Sea, Antarctica. In situ marine assemblages were documented in at least three of the six lithostratigraphic units, and it is likely that the remaining three interbedded diamicton units are also marine in origin. Peak foraminiferal diversities are documented in Unit 3.1 (73 species) and Unit 2.2 (32 species). Calcareous benthics dominate the assemblages, but may be accompanied by abundant occurrences of the planktonic Neogloboquadrina pachyderma. Low diversity agglutinated faunas appear in the uppermost strata of Units 4.1 and 2.2. A close relationship between lithofacics and foraminiferal biofacies points to marine environments that alternated between proximity to and distance from active glaciers and iceshelf fronts, with associated variations in salinity, sea-surface ice cover and the levels of rainout from debris-laden ice