1
00:00:00,120 --> 00:00:01,920
Speaker 1: This Day in History Class is a production of I

2
00:00:02,040 --> 00:00:07,640
Speaker 1: Heart Radio. Hi, I'm Eves and Welcome to This Day

3
00:00:07,640 --> 00:00:11,200
Speaker 1: in History Class, a show that uncovers a little bit

4
00:00:11,200 --> 00:00:24,480
Speaker 1: more about history. Every day. Today is July fiveen. The

5
00:00:24,560 --> 00:00:29,760
Speaker 1: day was July five. Dolly the sheep, the first mammal

6
00:00:29,800 --> 00:00:32,880
Speaker 1: to be successfully cloned from an adult sale, was born,

7
00:00:33,720 --> 00:00:38,400
Speaker 1: though her birth was not announced until A clone is

8
00:00:38,440 --> 00:00:41,600
Speaker 1: a living organism that has the same genetic information as

9
00:00:41,640 --> 00:00:46,240
Speaker 1: another organism. Keith Campbell, Ian Wilmot and others at the

10
00:00:46,320 --> 00:00:50,320
Speaker 1: Rosalind Institute in Scotland cloned Dolly using a method called

11
00:00:50,320 --> 00:00:56,040
Speaker 1: somatic sale nuclear transfer or sc n T. In this method,

12
00:00:56,200 --> 00:00:59,000
Speaker 1: the nucleus of an egg shil is removed and replaced

13
00:00:59,240 --> 00:01:02,560
Speaker 1: with the nucleus of a donor adult Sell. The animal

14
00:01:02,640 --> 00:01:05,400
Speaker 1: born from this process will have nearly the same DNA

15
00:01:05,760 --> 00:01:09,640
Speaker 1: as the original donor Sell. Dolly was not the first

16
00:01:09,680 --> 00:01:12,360
Speaker 1: mammal to be cloned. The first was a sheep that

17
00:01:12,440 --> 00:01:14,920
Speaker 1: was cloned from an embryo cell and born in nineteen

18
00:01:14,959 --> 00:01:19,119
Speaker 1: eighty four in Cambridge, England. Two other sheep had been

19
00:01:19,120 --> 00:01:22,440
Speaker 1: cloned from embryonic sales grown at the Rosalind Institute lab

20
00:01:22,440 --> 00:01:26,479
Speaker 1: in nine and When Dolly was born, so were six

21
00:01:26,480 --> 00:01:29,360
Speaker 1: other sheep that were cloned from embryonic and fetal sills.

22
00:01:30,520 --> 00:01:32,960
Speaker 1: Dolly was the one to become famous because she was

23
00:01:33,000 --> 00:01:36,399
Speaker 1: cloned from an adult sell something believed to be impossible

24
00:01:36,480 --> 00:01:40,200
Speaker 1: at the time. Dolly's DNA came from a six year

25
00:01:40,240 --> 00:01:44,640
Speaker 1: old sheep. Once normal development was confirmed at six days,

26
00:01:44,880 --> 00:01:48,880
Speaker 1: the embryo was transferred to a surrogate mother. Dolly was

27
00:01:48,920 --> 00:01:52,840
Speaker 1: born on July five, nine. Out of two hundred and

28
00:01:52,880 --> 00:01:56,520
Speaker 1: seventy seven embryos researchers at the Rosalind Institute had attempted

29
00:01:56,560 --> 00:02:01,040
Speaker 1: to clone, Dolly was the only animal born. Initially, Dolly

30
00:02:01,120 --> 00:02:04,480
Speaker 1: was code named six L L three. Stockman who helped

31
00:02:04,520 --> 00:02:07,639
Speaker 1: give birth to Dolly suggested the name Dolly after Dolly

32
00:02:07,680 --> 00:02:10,520
Speaker 1: Parton because the cell used to clone her came from

33
00:02:10,560 --> 00:02:14,800
Speaker 1: a mammary gland. The Rosalind Institute announced Dolly's birth on

34
00:02:14,840 --> 00:02:19,680
Speaker 1: February two seven, along with the publication of their research

35
00:02:19,720 --> 00:02:23,640
Speaker 1: results related to the cloning. Dolly lived at the Rosalind

36
00:02:23,639 --> 00:02:26,400
Speaker 1: Institute with other sheep. She had six lambs with a

37
00:02:26,400 --> 00:02:31,400
Speaker 1: Welsh mountain ram named David, and they were called Bonnie, Sally, Rosie, Lucy,

38
00:02:31,600 --> 00:02:36,440
Speaker 1: Darcy and Cotton. When Dolly was one, DNA analysis did

39
00:02:36,560 --> 00:02:40,120
Speaker 1: show that her telomeres were shorter than normal. Telomeres are

40
00:02:40,160 --> 00:02:44,040
Speaker 1: repetitive nucleotide sequences at the end of chromosomes that form

41
00:02:44,080 --> 00:02:46,760
Speaker 1: a cap to protect them from deteriorating or fusing with

42
00:02:46,840 --> 00:02:52,320
Speaker 1: other chromosomes. As animals age and sales divide, telomeres shortened,

43
00:02:52,520 --> 00:02:56,120
Speaker 1: and eventually the chromosome cannot be replicated, triggering the sale

44
00:02:56,160 --> 00:02:59,959
Speaker 1: to die. Dolly's short telomeres could have meant she was

45
00:03:00,000 --> 00:03:03,239
Speaker 1: physically older than her true age, but health tests did

46
00:03:03,280 --> 00:03:07,200
Speaker 1: not show that she was aging quickly or prematurely. In

47
00:03:07,240 --> 00:03:10,520
Speaker 1: two thousand, Dolly, along with other sheep at the institute,

48
00:03:10,840 --> 00:03:14,560
Speaker 1: was infected with j S RV, a virus that causes

49
00:03:14,600 --> 00:03:18,320
Speaker 1: contagious lung cancer and sheep, and in two thousand one,

50
00:03:18,440 --> 00:03:22,959
Speaker 1: when Dolly was four years old, she was diagnosed with arthritis.

51
00:03:23,000 --> 00:03:26,600
Speaker 1: She was treated successfully with anti inflammatory medicine, but it

52
00:03:26,720 --> 00:03:31,200
Speaker 1: wasn't clear what caused the arthritis. Dolly lived a healthy

53
00:03:31,240 --> 00:03:35,200
Speaker 1: life until February two thousand and three, when staff reported

54
00:03:35,240 --> 00:03:38,240
Speaker 1: that she was coughing. When the team conducted a CT

55
00:03:38,400 --> 00:03:41,920
Speaker 1: scan on Dolly days later, they found tumors growing in

56
00:03:41,960 --> 00:03:45,800
Speaker 1: her chest. She had progressive lung disease caused by infection

57
00:03:45,920 --> 00:03:50,600
Speaker 1: with j s RB. She was euthanized on February fourteen,

58
00:03:50,960 --> 00:03:54,559
Speaker 1: when she was six years old. The average life expectancy

59
00:03:54,640 --> 00:03:57,120
Speaker 1: for a thin Dorset sheet like Dolly was ten to

60
00:03:57,160 --> 00:04:00,240
Speaker 1: twelve years, but researchers did not think her early death

61
00:04:00,320 --> 00:04:03,880
Speaker 1: was related to her being a clone. Many other large

62
00:04:03,920 --> 00:04:07,080
Speaker 1: animals were cloned after Dolly demonstrated that cloning from an

63
00:04:07,080 --> 00:04:10,800
Speaker 1: adult somatic sale could be successful, including clones of Dolly.

64
00:04:11,920 --> 00:04:15,880
Speaker 1: Dolly's cloning also encouraged a new understanding of sale modification

65
00:04:16,320 --> 00:04:20,960
Speaker 1: and drove advances in stem cell research and therapy. Of course,

66
00:04:21,120 --> 00:04:25,719
Speaker 1: Dolly's cloning was highly controversial, leading to discussions of livestock cloning,

67
00:04:26,080 --> 00:04:30,200
Speaker 1: human cloning, and de extinction. I'm eve Chef Coote and

68
00:04:30,240 --> 00:04:32,960
Speaker 1: hopefully you know a little more about history today. Thank

69
00:04:33,000 --> 00:04:37,320
Speaker 1: you did yesterday. Keep up with us on Twitter, Instagram

70
00:04:37,360 --> 00:04:42,960
Speaker 1: and Facebook at t d I HC podcast. You can

71
00:04:43,000 --> 00:04:45,960
Speaker 1: subscribe to This Day in History class on Apple Podcasts,

72
00:04:46,200 --> 00:04:49,000
Speaker 1: the I Heart Radio app, or wherever you get your podcasts.

73
00:04:49,839 --> 00:05:01,160
Speaker 1: Come back tomorrow for another tidbit from history. For more

74
00:05:01,200 --> 00:05:04,640
Speaker 1: podcasts from My Heart radio, visit the iHeartRadio app, Apple podcasts,

75
00:05:04,720 --> 00:05:06,400
Speaker 1: or wherever you listen to your favorite shows.