Cartilage is an inconvenient tissue for the isolation of mRNA, and this has hampered studies of its component mRNAs conducted to date. Here, we describe the preparation of a good quality cDNA library from mouse growth cartilage (mGC). A total of 1.7 microg of poly(A)+ RNA was obtained from about 1200 pieces of the mGC zone of 60 young mice (BALB/c, 4 weeks old). Using this poly(A)+ RNA, we constructed a cDNA library using the pAP3neo vector by the linker-primer method. The complexity of the cDNA library was 2.6 x 106 colony-forming units (cfu), which signified that almost all of the mRNA components in the mGC were present in this cDNA library. From this library, 1401 clones were randomly selected and their insert sizes were examined. Of these clones, 166 (12%) had no inserts, 466 (33%) had inserts ranging in size from 0-0.9 kbp, 480 (34%) had inserts of 1. 0-1.9 kbp, 162 (12%) had inserts of 2.0-2.9 kbp, and 127 (9%) had sizes greater than 3.0 kbp. The average insert size was 1.45 kbp. The number of cfu and the insert size data qualified this library as of reasonably good quality. Clones with an insert size greater than 1 kbp (769 clones) were sequenced from their 5' ends. Among the 769 clones examined, 608 gave sequence data. Among these, 196 (32%) were unknown, 2 were only poly A, and 410 (67%) coded for known proteins. Of these, 55 clones coded for type II (pro)collagen, 54 for osteonectin, and 22 for other cartilage collagens (type IX, type X, and type XI). The rest included cartilage extracellular matrix genes, general cellular genes, and others. To judge further the quality of the library, 45 species coding for type II collagen chain were aligned based on their 5' end sequences. Three species (7%) contained almost the full-length insert, and the shortest one was 1. 5 kbp in length (full-length 5.6 kbp). These data show that this cDNA library is of reasonably good quality, making it likely that the large number of unknown inserts (32%) will provide a suitable pool for the identification and functional determination of new GC genes.
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Appl Microbiol Biotechnol
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Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark.
One strategy for CO mitigation is using photosynthetic microorganisms to sequester CO under high concentrations, such as in flue gases. While elevated CO levels generally promote growth, excessively high levels inhibit growth through uncertain mechanisms. This study investigated the physiology of the cyanobacterium Synechocystis sp.
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National Key Laboratory for Germplasm Innovation and Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China.
GRAS, termed after gibberellic acid insensitive (GAI), RGA (repressor of GA1), and SCR (scarecrow), is a plant-specific transcription factor crucial for plant development and stress response. However, understanding of the functions played by the GRAS members and their target genes in citrus is limited. In this study, we identified a cold stress-responsive GRAS gene from , designated as PtrPAT1, by yeast one-hybrid library screening using the promoter of , a betaine aldehyde dehydrogenase (BADH)-like gene.
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State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University;
The extent of functional sequences within the human genome is a pivotal yet debated topic in biology. Although high-throughput reverse genetic screens have made strides in exploring this, they often limit their scope to known genomic elements and may introduce non-specific effects. This underscores the urgent need for novel functional genomics tools that enable a deeper, unbiased understanding of genome functionality.
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Department of Chronic Disease Epidemiology, Yale School of Public Health, New Haven, Connecticut, USA.
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