Table 1. Distribution of candidate tRNase Zs from representative metazoans.

Species	Protein name	Form	Accession number	Database	No. aa#	EST
Deuterostomes
Branchiostoma floridae	BflTRZ1	tRNase ZS	XP_002598072.1	NCBI	367*	+
Branchiostoma floridae	BflTRZ2	tRNase ZL	XP_002603583.1	NCBI	785*
Canis familiaris	CfaTRZ1	tRNase ZS	XP_849493.1	NCBI	374	+
Canis familiaris	CfaTRZ2	tRNase ZL	XP_546630.2	NCBI	821	+
Ciona intestinalis	CinTRZ1	tRNase ZS	299192	Metazome	383	+
Ciona intestinalis	CinTRZ2	tRNase ZL	295609	Metazome	727	+
Danio rerio	DreTRZ1	tRNase ZS	NP_001003503.1	NCBI	372	+
Danio rerio	DreTRZ2	tRNase ZL	XP_003198113.1	NCBI	895	+
Homo sapiens	HsaTRZ1	tRNase ZS	NP_061166.1	NCBI	363	+
Homo sapiens	HsaTRZ2	tRNase ZL	NP_060597.4	NCBI	826	+
Loxodonta africana	LafTRZ1	tRNase ZS	ENSLAFP00000001283	Ensembl	364
Loxodonta africana	LafTRZ2	tRNase ZL	ENSLAFP00000025345	Ensembl	819
Mus musculus	MmuTRZ1	tRNase ZS	NP_444485.2	NCBI	362	+
Mus musculus	MmuTRZ2	tRNase ZL	CAI24609	NCBI	824	+
Salmo salar	SsaTRZ1	tRNase ZS		NCBI	370	+
Salmo salar	SsaTRZ2	tRNase ZL	C0H8T6	Uniprot	875	+
Strongylocentrotus purpuratus	SpuTRZ1	tRNase ZS	XP_001189573.1	NCBI	362
Strongylocentrotus purpuratus	SpuTRZ2	tRNase ZL	XP_783904.2	NCBI	931*	+
Xenopus tropicalis	XtrTRZ1	tRNase ZS	476074	Metazome	363	+
Xenopus tropicalis	XtrTRZ2	tRNase ZL	157533	Metazome	835*	+
Protostomes
Bombyx mori	BmoTRZ1	tRNase ZL	Bmb008309	Metazome	889*	+
Caenorhabditis elegans	CelTRZ1	tRNase ZL	NP_001023109.1	NCBI	833	+
Capitella teleta	CteTRZ1	tRNase ZL	228344	JGI	758	+
Capitella teleta	CteTRZ2	tRNase ZL-Like	218896	JGI	738	+
Drosophila melanogaster	DmeTRZ1	tRNase ZL	NP_724916.1	NCBI	766	+
Lottia gigantea	LgiTRZ1	tRNase ZS	218281	JGI	356	+
Lottia gigantea	LgiTRZ2	tRNase ZL	156489	JGI	738*	+
Lottia gigantea	LgiTRZ3	tRNase ZL	230203	JGI	780	+
Tribolium castaneum	TcaTRZ1	tRNase ZL	XP_968692.2	NCBI	827	+
Basal Metazoans
Amphimedon queenslandica	AquTZ1	tRNase ZS	Aqu1.217211	JGI	373*
Amphimedon queenslandica	AquTZ2	tRNase ZL	XP_003385508.1	NCBI	712*
Hydra magnipapillata	HmaTRZ1	tRNase ZS	Hma2.228140	JGI	359	+
Hydra magnipapillata	HmaTRZ2	tRNase ZL	Hma2.206546	JGI	723*
Nematostella vectensis	NveTRZ1	tRNase ZS	186754	JGI	342	+
Nematostella vectensis	NveTRZ2	tRNase ZL	11980	JGI	827*
Nematostella vectensis	NveTRZ3	tRNase ZL	108544	JGI	769*	+
Trichoplax adhaerens	TadTRZ1	tRNase ZL	B3RMG1	Uniprot	728*
Protozoans
Monosiga brevicollis	MbrTRZ1	tRNase ZS	25108	JGI	380*
Monosiga brevicollis	MbrTRZ2	tRNase ZL	23750	JGI	812*

^#The number of amino acids in metazoan tRNase Z proteins.

^*Indicates that mispredicted sequences obtained from the databases have been corrected.

A plus sign indicates that gene expression is confirmed by the presence of ESTs.