The complete chloroplast genome sequence of the chlorophycean green alga Scenedesmus obliquus reveals a compact gene organization and a biased distribution of genes on the two DNA strands

Table 2 Expanded genes in Scenedesmus and other UTC algal cpDNAs

Gene	Chlorella		Oltmannsiellopsis		Pseudendoclonium		Scenedesmus		Chlamydomonas
	Size (bp)	Factor^a	Size (bp)	Factor^a	Size (bp)	Factor^a	Size (bp)	Factor^a	Size (bp)	Factor^a
cemA ^b	801	1.6	1059	2.2	909	1.8	1278	2.6	1503	3.1
clpP	606	0.9	588	0.9	597	0.9	1614	2.3	1575	2.3
ftsH ^b	5163	1.9	6879	2.6	7791	2.9	10998	4.1	8916	3.3
infA ^b	240	1.2	222	1.1	330	1.6	306	1.5	– ^c	– ^c
rpoA	837	0.9	1527	1.6	1734	1.8	1437	1.5	2213 ^d	2.3
rpoB	3906	1.2	4251	1.3	6537	2.0	4896 ^e	1.5	4967 ^e	1.5
rpoC1	2511	1.3	3066	1.5	4737	2.4	4590	2.3	5739 ^e	2.9
rpoC2	4689	1.3	5580	1.5	10389	2.8	7659	2.1	9363	2.5
rps2	804	1.2	717	1.0	777	1.1	2747 ^e	4.0	2731 ^e	4.0
rps3	696	1.1	708	1.1	690	1.1	2103	3.3	2139	3.3
rps18 ^b	312	1.4	237	1.1	258	1.2	567	2.6	414	1.9
ycf1 ^b	2460	2.0	2427	2.0	2505	2.0	7008	5.7	5988	4.9

^a Expansion factor relative to the corresponding Mesostigma gene. Each value was obtained by dividing the size of the UTC algal gene by the size of the corresponding Mesostigma gene.
^b Genes also expanded in streptophyte cpDNAs. Note that the ftsH gene is designated as ycf2 in Chlorella, Chlamydomonas and land plants cpDNAs.
^c infA is missing in Chlamydomonas cpDNA
^d Size derived from our unpublished sequence data. A portion of the rpoA region is not annotated in GenBank:NC_005353 as a result of a sequencing error introducing a frameshift mutation.
^e Gene occurring as two independent ORFs. The indicated size includes the spacer separating the ORFs.

ISSN: 2730-7182