Statistics

• piRBase contains information from 44 species, including Human.

#	Abbreviation	Species
1	aca	Sea hare
2	bmo	Silkworm
3	bta	Cow
4	cel	C. elegans
5	cja	Marmoset
6	der	D. erecta
7	dme	D. melanogaster
8	dre	Zebrafish
9	dvi	D. virilis
10	dya	D. yakuba
11	eca	Horse
12	gga	Chicken
13	hsa	Human
14	mfa	Crab-eating macaque
15	mml	Rhesus
16	mmu	Mouse
17	nve	Starlet sea anemone
18	ocu	Rabbit
19	rno	Rat
20	ssc	Pig
21	tbe	Tree shrew
22	xtr	X. tropicalis
23	ame	giant panda
24	bgl	B. glabrata
25	c26	Caenorhabditis sp 26
26	c31	Caenorhabditis sp 31
27	c32	Caenorhabditis sp 32
28	cbn	C. brenneri
29	cbr	C. briggsae
30	cca	C. castelli
31	cdo	C. doughertyi
32	cma	C. macrosperma
33	crm	C. remanei
34	cvi	C. virilis
35	dpa	D. pachys
36	hco	barber pole worm
37	hpo	H. polygyrus
38	nbr	N. brasiliensis
39	oti	O. tipulae
40	pox	P. oxycercus
41	ppc	P. pacificus
42	psa	P. sambesii
43	spa	Mud crab
44	mau	Golden hamster

• piRBase has the largest number of piRNA sequences compared to other similar databases.
    More than 181 million unique piRNA sequences from 44 species are included.
    Mouse(mmu) has the largest number of piRNA sequences with 68,542,499, which is followed by D.melanogaster(dme), Cow(bta) and Human(hsa).

• piRBase contains 440 datasets from 44 species.
    Mouse(mmu) has the largest number of datasets with 113, which is followed by Human(hsa) and D.melanogaster(dme).
    Tree shrew(tbe) and 23 other species have only one data set.

• Overall, the length of piRNAs ranges from 20nt to 36nt.
    The curve of some species such as Sea hare(aca) and Tree shrew(tbe) contains a single peak between 28 and 30nt, while the curve of several species like mud crab(spa) contains a single peak between 25nt and 27nt.
    In addition, the curve of a few species such as Starlet sea anemone(nve) and horse(eca) contains more than one peaks.