0	8	Retinoic	retinoic	JJ
9	13	acid	acid	NN
14	27	downmodulates	downmodulate	VBZ
28	37	erythroid	erythroid	JJ
38	53	differentiation	differentiation	NN
54	57	and	and	CC
58	63	GATA1	gata1	NN
64	74	expression	expression	NN
75	77	in	in	IN
78	86	purified	purify	VBN
87	103	adult-progenitor	adult-progenitor	JJ
104	111	culture	culture	NN
111	112	.	.	.

114	123	All-trans	all-trans	JJ
124	132	retinoic	retinoic	JJ
133	137	acid	acid	NN
138	139	(	(	(
139	141	RA	RA	NNP
141	142	)	)	)
143	145	is	be	VBZ
146	148	an	an	DT
149	158	important	important	JJ
159	168	morphogen	morphogen	NN
169	171	in	in	IN
172	182	vertebrate	vertebrate	NN
183	194	development	development	NN
194	195	,	,	,
196	197	a	a	DT
198	204	normal	normal	JJ
205	216	constituent	constituent	NN
217	219	in	in	IN
220	225	human	human	JJ
226	231	adult	adult	JJ
232	237	blood	blood	NN
238	241	and	and	CC
242	244	is	be	VBZ
245	249	also	also	RB
250	258	involved	involve	VBN
259	261	in	in	IN
262	265	the	the	DT
266	273	control	control	NN
274	276	of	of	IN
277	281	cell	cell	NN
282	288	growth	growth	NN
289	292	and	and	CC
293	308	differentiation	differentiation	NN
309	311	in	in	IN
312	317	acute	acute	JJ
318	331	promyelocytic	promyelocytic	JJ
332	340	leukemia	leukemia	NN
340	341	.	.	.

342	344	We	we	PRP
345	349	have	have	VBP
350	358	examined	examine	VBN
359	362	the	the	DT
363	370	effects	effect	NNS
371	373	of	of	IN
374	376	RA	RA	NNP
377	379	on	on	IN
380	386	normal	normal	JJ
387	400	hematopoiesis	hematopoiesis	NN
401	403	by	by	IN
404	409	using	use	VBG
410	415	early	early	JJ
416	429	hematopoietic	hematopoietic	JJ
430	440	progenitor	progenitor	NN
441	446	cells	cell	NNS
447	448	(	(	(
448	451	HPC	HPC	NNP
451	452	)	)	)
453	464	stringently	stringently	RB
465	473	purified	purify	VBN
474	478	from	from	IN
479	484	adult	adult	JJ
485	495	peripheral	peripheral	JJ
496	501	blood	blood	NN
501	502	.	.	.

503	505	In	in	IN
506	518	clonogenetic	clonogenetic	JJ
519	524	fetal	fetal	JJ
525	529	calf	calf	NN
530	548	serum-supplemented	serum-supplemented	JJ
549	550	(	(	(
550	554	FCS+	fcs+	JJ
554	555	)	)	)
556	558	or	or	CC
559	575	-nonsupplemented	-nonsupplemented	JJ
576	577	(	(	(
577	581	FCS-	fcs-	JJ
581	582	)	)	)
583	590	culture	culture	NN
591	598	treated	treat	VBN
599	603	with	with	IN
604	614	saturating	saturating	JJ
615	621	levels	level	NNS
622	624	of	of	IN
625	638	interleukin-3	interleukin-3	NN
639	640	(	(	(
640	644	IL-3	IL-3	NNP
644	645	)	)	)
646	668	granulocyte-macrophage	granulocyte-macrophage	JJ
669	687	colony-stimulating	colony-stimulating	JJ
688	694	factor	factor	NN
695	696	(	(	(
696	702	GM-CSF	GM-CSF	NNP
702	703	)	)	)
704	707	and	and	CC
708	722	erythropoietin	erythropoietin	NN
723	724	(	(	(
724	726	Ep	Ep	NNP
726	727	)	)	)
728	729	(	(	(
729	737	combined	combine	VBN
738	742	with	with	IN
743	748	c-kit	c-kit	NN
749	755	ligand	ligand	NN
756	758	in	in	IN
759	773	FCS(-)-culture	FCS(-)-culture	NNP
774	784	conditions	condition	NNS
784	785	)	)	)
785	786	,	,	,
787	789	RA	RA	NNP
790	797	induces	induce	VBZ
798	799	a	a	DT
800	808	dramatic	dramatic	JJ
809	823	dose-dependent	dose-dependent	JJ
824	829	shift	shift	NN
830	834	from	from	IN
835	844	erythroid	erythroid	JJ
845	847	to	to	TO
848	864	granulomonocytic	granulomonocytic	JJ
865	871	colony	colony	NN
872	881	formation	formation	NN
881	882	,	,	,
883	886	the	the	DT
887	893	latter	latter	JJ
894	902	colonies	colony	NNS
903	908	being	be	VBG
909	920	essentially	essentially	RB
921	932	represented	represent	VBN
933	935	by	by	IN
936	948	granulocytic	granulocytic	JJ
949	955	clones	clone	NNS
955	956	.	.	.

957	961	This	this	DT
962	967	shift	shift	NN
968	970	is	be	VBZ
971	981	apparently	apparently	RB
982	985	not	not	RB
986	992	caused	cause	VBN
993	995	by	by	IN
996	997	a	a	DT
998	1009	recruitment	recruitment	NN
1010	1020	phenomenon	phenomenon	NN
1020	1021	,	,	,
1022	1029	because	because	IN
1030	1032	in	in	IN
1033	1037	FCS+	fcs+	JJ
1038	1045	culture	culture	NN
1045	1046	,	,	,
1047	1050	the	the	DT
1051	1056	total	total	JJ
1057	1063	number	number	NN
1064	1066	of	of	IN
1067	1075	colonies	colony	NNS
1076	1078	is	be	VBZ
1079	1082	not	not	RB
1083	1096	significantly	significantly	RB
1097	1105	modified	modify	VBN
1106	1108	by	by	IN
1109	1111	RA	RA	NNP
1112	1120	addition	addition	NN
1120	1121	.	.	.

1122	1124	In	in	IN
1125	1129	FCS-	fcs-	NN
1130	1147	liquid-suspension	liquid-suspension	NN
1148	1155	culture	culture	NN
1156	1168	supplemented	supplement	VBN
1169	1173	with	with	IN
1174	1184	saturating	saturate	VBG
1185	1187	Ep	Ep	NNP
1188	1193	level	level	NN
1194	1197	and	and	CC
1198	1206	low-dose	low-dose	JJ
1207	1218	IL-3/GM-CSF	IL-3/GM-CSF	NNP
1218	1219	,	,	,
1220	1225	adult	adult	JJ
1226	1229	HPC	HPC	NNP
1230	1237	undergo	undergo	VBP
1238	1248	unilineage	unilineage	JJ
1249	1263	erythropoietic	erythropoietic	JJ
1264	1279	differentiation	differentiation	NN
1279	1280	:	:	:
1281	1285	Here	here	RB
1286	1291	again	again	RB
1291	1292	,	,	,
1293	1302	treatment	treatment	NN
1303	1307	with	with	IN
1308	1317	high-dose	high-dose	JJ
1318	1320	RA	RA	NNP
1321	1328	induces	induce	VBZ
1329	1330	a	a	DT
1331	1336	shift	shift	NN
1337	1341	from	from	IN
1342	1345	the	the	DT
1346	1355	erythroid	erythroid	JJ
1356	1358	to	to	TO
1359	1371	granulocytic	granulocytic	JJ
1372	1387	differentiation	differentiation	NN
1388	1395	pathway	pathway	NN
1395	1396	.	.	.

1397	1404	Studies	Study	NNPS
1405	1407	on	on	IN
1408	1410	RA	RA	NNP
1411	1424	time-response	time-response	JJ
1425	1427	or	or	CC
1428	1433	pulse	pulse	NN
1434	1443	treatment	treatment	NN
1444	1446	in	in	IN
1447	1456	semisolid	semisolid	JJ
1457	1459	or	or	CC
1460	1466	liquid	liquid	JJ
1467	1474	culture	culture	NN
1475	1479	show	show	VBP
1480	1484	that	that	IN
1485	1490	early	early	JJ
1491	1493	RA	RA	NNP
1494	1502	addition	addition	NN
1503	1505	is	be	VBZ
1506	1510	most	most	RBS
1511	1520	effective	effective	JJ
1520	1521	,	,	,
1522	1526	thus	thus	RB
1527	1537	indicating	indicate	VBG
1538	1542	that	that	IN
1543	1548	early	early	JJ
1549	1552	but	but	CC
1553	1556	not	not	RB
1557	1561	late	late	JJ
1562	1565	HPC	HPC	NNP
1566	1569	are	be	VBP
1570	1579	sensitive	sensitive	JJ
1580	1582	to	to	TO
1583	1586	its	its	PRP$
1587	1593	action	action	NN
1593	1594	.	.	.

1595	1597	We	we	PRP
1598	1602	then	then	RB
1603	1611	analyzed	analyze	VBD
1612	1615	the	the	DT
1616	1626	expression	expression	NN
1627	1629	of	of	IN
1630	1633	the	the	DT
1634	1640	master	master	NN
1641	1646	GATA1	gata1	NN
1647	1651	gene	gene	NN
1651	1652	,	,	,
1653	1658	which	which	WDT
1659	1666	encodes	encode	VBZ
1667	1668	a	a	DT
1669	1675	finger	finger	NN
1676	1689	transcription	transcription	NN
1690	1696	factor	factor	NN
1697	1705	required	require	VBN
1706	1709	for	for	IN
1710	1716	normal	normal	JJ
1717	1726	erythroid	erythroid	JJ
1727	1738	development	development	NN
1738	1739	;	;	:
1740	1748	addition	addition	NN
1749	1751	of	of	IN
1752	1754	RA	RA	NNP
1755	1757	to	to	TO
1758	1761	HPC	HPC	NNP
1762	1772	stimulated	stimulate	VBN
1773	1777	into	into	IN
1778	1788	unilineage	unilineage	JJ
1789	1803	erythropoietic	erythropoietic	JJ
1804	1819	differentiation	differentiation	NN
1820	1822	in	in	IN
1823	1829	liquid	liquid	JJ
1830	1837	culture	culture	NN
1838	1844	caused	cause	VBD
1845	1846	a	a	DT
1847	1856	virtually	virtually	RB
1857	1865	complete	complete	JJ
1866	1876	inhibition	inhibition	NN
1877	1879	of	of	IN
1880	1885	GATA1	gata1	NN
1886	1890	mRNA	mrna	NN
1891	1900	induction	induction	NN
1900	1901	.	.	.

1902	1907	These	these	DT
1908	1915	results	result	NNS
1916	1924	indicate	indicate	VBP
1925	1929	that	that	IN
1930	1932	RA	RA	NNP
1933	1941	directly	directly	RB
1942	1950	inhibits	inhibit	VBZ
1951	1954	the	the	DT
1955	1964	erythroid	erythroid	JJ
1965	1980	differentiation	differentiation	NN
1981	1988	program	program	NN
1989	1991	at	at	IN
1992	1995	the	the	DT
1996	2001	level	level	NN
2002	2004	of	of	IN
2005	2010	early	early	JJ
2011	2016	adult	adult	JJ
2017	2020	HPC	HPC	NNP
2020	2021	,	,	,
2022	2025	and	and	CC
2026	2029	may	may	MD
2030	2034	lead	lead	VB
2035	2037	to	to	TO
2038	2039	a	a	DT
2040	2045	shift	shift	NN
2046	2050	from	from	IN
2051	2054	the	the	DT
2055	2064	erythroid	erythroid	JJ
2065	2067	to	to	TO
2068	2080	granulocytic	granulocytic	JJ
2081	2096	differentiation	differentiation	NN
2097	2104	pathway	pathway	NN
2104	2105	.	.	.

2106	2110	This	this	DT
2111	2121	phenomenon	phenomenon	NN
2122	2124	is	be	VBZ
2125	2135	correlated	correlate	VBN
2136	2140	with	with	IN
2141	2151	inhibition	inhibition	NN
2152	2154	of	of	IN
2155	2160	GATA1	gata1	NN
2161	2170	induction	induction	NN
2171	2173	in	in	IN
2174	2177	the	the	DT
2178	2183	early	early	JJ
2184	2190	stages	stage	NNS
2191	2193	of	of	IN
2194	2208	erythropoietic	erythropoietic	JJ
2209	2224	differentiation	differentiation	NN
2224	2225	.	.	.