AbstractThe SFTPB (surfactant, pulmonary-associated protein B)

gene on human chromosome 2p11.2 encodes an amphipathic surfactant protein essential for lung function and homeostasis after birth. The SFTPB gene has been investigated to have transcript variants related with transposable elements (LTR7B and AluSx). We investigated the evolutionary aspect and molecular characterization of SFTPB gene using genomic DNAs and RNAs from various primate samples. LTR7B and AluSx elements within the SFTPB gene have been integrated into ancestor genome before the divergence of simian and prosimian. Alu recombination-mediated deletion (ARMD) event has been occurred after the divergence of New World monkeys and Old World monkeys in SFTPB gene 3’ UTR region. Transcript variants (306 bp and 463 bp) were newly identified by comparative RT-PCR analysis. Original transcript (419 bp) shows ubiquitous expression in various tissues and TE fusion transcript (841 bp) shows the lung specific expression in human. Taken together, integration event of LTR7B and AluSx on SFTPB gene seem to cause a lineage specific exonization event via general exonization event (New World monkeys and prosimian), ARMD event (Old World monkeys and hominoids), and alternative splicing (human) during the primate evolution.

Ja-Rang Lee1, Jae-Won Huh1,2, Dae-Soo Kim3, Hong-Seok Ha1, Kung Ahn1, Yun-Ji Kim1, Kyu-Tae Chang2, and Heui-Soo Kim1,*

1 Division of Biological Sciences, College of Natural Sciences, Pusan National University, Busan 609-735, Korea2 National Primate Research Center (NPRC), KRIBB, Ochang, Chungbuk 363-883, Republic of Korea

3 Korea Bioinformation Center, KRIBB, Daejeon 305-806, Korea

1. Han, K., Lee J., Meyer, T. J., Wang, J., Sen, S. K., Srikanta, D., Liang, P. & Batzer, M. A. (2007). Alu recombination-mediated structural deletions in the chimpanzee genome. PLoS Genet. 3, 1939-1949.

2. Clark JC, Wert SE, Bachurski CJ, Stahlman MT, Stripp BR, Weaver TE, Whitsett JA. 1995. Targeted disruption of the surfactant protein B gene disrupts surfactant homeostasis, causing respiratory failure in newborn mice. Proc. Natl. Acad. Sci. USA. 92: 7794-7798.

References

Materials & Methods

BioinformaticsBioinformatics

Genomic DNA Genomic DNA & cDNA& cDNA

RT-PCRRT-PCRHuman, Rhesus monkey & Marmoset(30 cycle)

; Various tissues

PCR & Cloning PCR & Cloning of PCR productof PCR product

30 cycle; 94 - 40 sec, 56 - 30 sec, 72 - 40 ℃ ℃ ℃

sec

Qiaquick Gel-extraction, Promega T-easy Vector,

EcoR-I(DH5α)

http://www.primate.or.kr/HESAS/

Genomic DNA of various primate and human

cDNA of various tissues of human, rhesus

monkey & marmoset

IntroductionOther region

16%

Gene-related Sequence

36%

LINE

20%

SINE

13%

Cod

ing

sequ

ence

3%

Pseu

doge

ne

1%

HERV element

8%

DNA ele

men

t

3%

Results & DiscussionChr. 2

1 2 11_A10NM_198843.1 638

bpS1

AS2

1 2 10NM_000542.2

11_B

2p11.2

SFTPB Gene

Structure

638 bp

S1

AS2

SFTPB Gene Expression in Various Tissues of Human

841 bp

306 bp

G3PDH 120 bp

Adr

enal

gla

nd

Bon

e m

arro

w

Cer

ebel

lum

Who

le b

rain

Fet

al b

rain

Fet

al li

ver

Hea

rt

Kid

ney

Mar

ker

Liv

er

Lun

g

Pla

cent

a

Mar

ker

Tes

tis

Thy

mus

Pro

stat

e

Saliv

ary

glan

d

Thy

roid

Ute

rus

Tra

chea

Skel

etal

mus

cle

Spin

al c

ord

Adr

enal

gla

nd

Bon

e m

arro

w

Cer

ebel

lum

Who

le b

rain

Fet

al b

rain

Fet

al li

ver

Hea

rt

Kid

ney

Mar

ker

Liv

er

Lun

g

Pla

cent

a

Mar

ker

Tes

tis

Thy

mus

Pro

stat

e

Saliv

ary

glan

d

Thy

roid

Ute

rus

Tra

chea

Skel

etal

mus

cle

Spin

al c

ord

419 bp

G3PDH 120 bp

841 bpS AS

NM_198843.1

New Transcript

NM_000542.2

New Transcript

419 bpS AS

463 bp

Cer

ebel

lum

Cer

ebru

m

Stom

ach

Pan

crea

s

Adr

enal

gla

nd

Hea

rt

Kid

ney

Liv

er

Lun

g

Tes

tis

Mar

ker

Tra

chea

Sple

en

Cec

um

Mar

ker

Rec

tum

Uri

ne b

ladd

er

Gul

let

Duo

denu

m

Ton

gue

Jeju

num

Saliv

ary

glan

d

Col

on

Ileu

m

306 bp

G3PDH 120 bp

Adr

enal

gla

nd

Cer

ebel

lum

Cer

ebru

m

Hea

rt

Kid

ney

Liv

er

Lun

g

Tes

tis

Mar

ker

Tra

chea

Sple

en

Cec

um

Mar

ker

Rec

tum

Uri

ne b

ladd

er

Gul

let

Stom

ach

Duo

denu

m

Ton

gue

Jeju

num

Pan

crea

s

Saliv

ary

glan

d

Col

on

Ileu

m

G3PDH 120 bp

463 bp

SFTPB Gene Expression in Various Tissues of Rhesus monkey

419 bp

SFTPB Gene Expression in Various Tissues of New World monkeys

Mar

ker

Bra

in

Hea

rt

Kid

ney

Liv

er

Lu

ng

Mar

ker

Cer

ebel

lum

Hea

rt

Kid

ney

Lu

ng

Ute

rus

306 bp

G3PDH 120 bp

306 bp

G3PDH 120 bp

Mar

ker

Cer

ebel

lum

Hea

rt

Kid

ney

Liv

er

Lu

ng

Cer

ebel

lum

Hea

rt

Kid

ney

Lu

ng

Ute

rus

Mar

ker

G3PDH 120 bp

463 bp419 bp

G3PDH 120 bp

638 bp

HU

CH

GO

OR

GI

JM RH

NMMar

ker

TA

RL

392 bp

HU

CH

GO

OR

GI

JM RH

NMMar

ker

TA

RL

763 bp

ARMD event and evolutionary aspect of the SFTPB gene

Integration lineage of HERV-H LTR and AluSx in the SFTPB gene

ARMD event

AluSg vs AluSx AluSxAluJ LTR7B?

AluSg AluSxAluJ LTR7B

Insertion of TEsInsertion of TEs

ARMD event

Alternative splicing